A metal is a chemical element that is a good conductor of both electricity and heat and forms cation and ionic bonds with non-metal.
Two properties of metals and non-metals:
Metals - They are malleable
-They are lustrous
Non-metals - they are poor conductor of heat and electricity compared to metals.
- they have high electronegativity
Three physical properties of metals:
1)Metals are solid at normal temperature except mercury
2)Metal transform to liquid from solid and to gas from liquid at definite temperatures which are high for most metals except mercury, sodium and potassium.
3)Metal reflects equally nearly all visible electromagnetic waves.
Tuesday, October 26, 2010
Monday, October 25, 2010
Waves
A wave is a disturbance that travels through time and space usually by the transfer of energy.There are different types of waves.
1)Longitudinal waves
2)Transverse waves
When the particles of the waves are displaced parallel to the direction of the propagation of the wave, it is called the longitudinal wave.
When the particles of the waves are displaced perpendicular to the propagation of the wave, it is called transverse wave.
You can also see the link given here for the progressive waves.
Next time we will learn about the properties of waves.
1)Longitudinal waves
2)Transverse waves
When the particles of the waves are displaced parallel to the direction of the propagation of the wave, it is called the longitudinal wave.
When the particles of the waves are displaced perpendicular to the propagation of the wave, it is called transverse wave.
You can also see the link given here for the progressive waves.
Next time we will learn about the properties of waves.
Sunday, October 24, 2010
Molecular formula of compounds
A compound is a chemical substance formed from two or more elements which can be separated into its constituent elements.
Now let's learn what is molecular formula of compounds.
Molecular formula of compounds shows the constituent elements of the compound with their symbols and number of atoms on each element contained in the compound.
We will learn how to represent some compounds in their molecular formula.
Lead carbonate - its molecular formulae is 2PbCO3.Pb(OH)2
Sodium Chloride - its molecular formula is NaCl
Carbon dioxide - CO2
Molecular formulas go one step beyond the empirical formula in that they express not only the correct ratio but the correct number of atoms in the molecule.
Now let's learn what is molecular formula of compounds.
Molecular formula of compounds shows the constituent elements of the compound with their symbols and number of atoms on each element contained in the compound.
We will learn how to represent some compounds in their molecular formula.
Lead carbonate - its molecular formulae is 2PbCO3.Pb(OH)2
Sodium Chloride - its molecular formula is NaCl
Carbon dioxide - CO2
Molecular formulas go one step beyond the empirical formula in that they express not only the correct ratio but the correct number of atoms in the molecule.
Monosaccharide structures
Carbohydrates are made up of carbon, hydrogen and oxygen.They are the most abundant source of energy for all living organism.Some of the other functions of carbohydrates include participation in cell growth, it also acts as chief structural material for cell walls in plants.
In their basic form, carbohydrates are simple sugars.These sugars are classified according to the number of carbons.
No.of carbons Category names Examples.
4 Tetrose erythrose
5 pentose arabinose
6 hexose allose
7 heptose sedoheptulose
The structures of carbohydrates are shown below:
D-erythrose D-rebose D-allose D-sedoheptulose
In their basic form, carbohydrates are simple sugars.These sugars are classified according to the number of carbons.
No.of carbons Category names Examples.
4 Tetrose erythrose
5 pentose arabinose
6 hexose allose
7 heptose sedoheptulose
The structures of carbohydrates are shown below:
D-erythrose D-rebose D-allose D-sedoheptulose
Friday, October 22, 2010
Food chain
Food chain of animals is defined as the transfer of food energy from one organism to another organism in an ecology.A food chain of animals starts with producers, then herbivores and ends with carnivores.
For example, herbs and plants are producers, grass-shoppers and cow are herbivores and tigers and wolves are carnivores.
A food web is a graphical representation of food chain system.An example of food web diagram is shown below:
You will find food chain for different animals according to their ecosystem.Animals can be terrestrial or aquatic.
For example, herbs and plants are producers, grass-shoppers and cow are herbivores and tigers and wolves are carnivores.
A food web is a graphical representation of food chain system.An example of food web diagram is shown below:
Pollution
Pollution has become one of the major issues nowadays.Pollution means undesirable state of natural environment being contaminated with harmful substances as a result of human activities.
Polythene pollution is one of the main problem which is created by widespread use of poly-bags and bottles.Polythene is non-bio-degradable.It is one of the causes of floods due to blockage of water.Because of industries and factories, water is being polluted leading to many health hazards.You will find many facts about water pollution in newspapers and magazines.Not only water, air is also polluted with unwanted chemicals in the form of solid particles or air.Carbon monoxide is one of the example of poisonous gas.
Steps have been taken to reduce the use of polythene by replacing it with recyclable paper bags.Limits have been given to different countries by International union in the release of carbon by industries.
Polythene pollution is one of the main problem which is created by widespread use of poly-bags and bottles.Polythene is non-bio-degradable.It is one of the causes of floods due to blockage of water.Because of industries and factories, water is being polluted leading to many health hazards.You will find many facts about water pollution in newspapers and magazines.Not only water, air is also polluted with unwanted chemicals in the form of solid particles or air.Carbon monoxide is one of the example of poisonous gas.
Steps have been taken to reduce the use of polythene by replacing it with recyclable paper bags.Limits have been given to different countries by International union in the release of carbon by industries.
Periodic table
The periodic table of elements is a table that provides information of elements in a systematic manner.It gives the information about the names and properties of elements.
The periodic table is divided into groups and periods.A group is a vertical column in a periodic table.There are 18 groups.The elements in a group have similar electronic configuration of the outermost shell.Electronic configuration of elements is the arrangement of electrons in the shells of an atom.A period is the horizontal row in the periodic table.Elements in a period have the same number of electron shells.
Elements of the Halogen family which are in group 17 in the periodic table is the most reactive elements whereas group 8A consists of elements which are considered as the least reactive elements.
The periodic table is divided into groups and periods.A group is a vertical column in a periodic table.There are 18 groups.The elements in a group have similar electronic configuration of the outermost shell.Electronic configuration of elements is the arrangement of electrons in the shells of an atom.A period is the horizontal row in the periodic table.Elements in a period have the same number of electron shells.
Elements of the Halogen family which are in group 17 in the periodic table is the most reactive elements whereas group 8A consists of elements which are considered as the least reactive elements.
Wednesday, October 20, 2010
Types of motion
What do you mean by Motion?
In physics, motion is the change in position of an object with respect to time.Motion is described in terms of velocity, acceleration, displacement, and time.
There are three types of motion:
1.Translatory motion
2.Rotational motion
3.Vibratory motion.
Translatory motion results in the change in location along some path such as moving of car down the highway.Rotational motion is the motion around an axis such as the rotation of the Earth.Vibratory motion is moving of an object back and forth such as moving of a pendulum.
In physics, motion is the change in position of an object with respect to time.Motion is described in terms of velocity, acceleration, displacement, and time.
There are three types of motion:
1.Translatory motion
2.Rotational motion
3.Vibratory motion.
Translatory motion results in the change in location along some path such as moving of car down the highway.Rotational motion is the motion around an axis such as the rotation of the Earth.Vibratory motion is moving of an object back and forth such as moving of a pendulum.
Chemical reaction
A chemical reaction is a process that results in the transformation of one set of chemical substance to another.Chemical reactions may be reversible or irreversible.
In a reversible reaction,the products of the reactions can be converted back to the reactants.Whereas in an irreversible reaction, the products of the reactions cannot be converted back to the reactants.
For example, Ammonium chloride which has been converted to ammonia and hydrogen chloride by heating can be reversed back to ammonium chloride when cold.
Example of irreversible reaction is given below:
NaOH + HCl –> NaCl + H2O + 13.7 kcal
In a reversible reaction,the products of the reactions can be converted back to the reactants.Whereas in an irreversible reaction, the products of the reactions cannot be converted back to the reactants.
For example, Ammonium chloride which has been converted to ammonia and hydrogen chloride by heating can be reversed back to ammonium chloride when cold.
Example of irreversible reaction is given below:
NaOH + HCl –> NaCl + H2O + 13.7 kcal
Properties of Hydrochloric acid
Historically, Hydrochloric acid is also called Muriatic acid.It is a solution of HCl in water.It is a highly corrosive, strong mineral acid with many industrial uses and is found naturally in gastric acid.
Some of the properties of Hydrochloric acid are:
a)It turns litmus paper from blue to red.
b) It turns methyl orange from yellow to pink.
c) It turns phenolpthalein (alkaline) from deep pink to colorless.
d)It reacts with metals to form their respective chlorides and liberates hydrogen.Example is given below;
There are many more properties of Hydrogenchloric acid.
Some of the properties of Hydrochloric acid are:
a)It turns litmus paper from blue to red.
b) It turns methyl orange from yellow to pink.
c) It turns phenolpthalein (alkaline) from deep pink to colorless.
d)It reacts with metals to form their respective chlorides and liberates hydrogen.Example is given below;
There are many more properties of Hydrogenchloric acid.
Dipole moment
Molecules are formed by sharing electrons. In a molecule, if there is a pair of electrons, one with negative charge and the other one with positive charge and if the center of the negative charge do not coincide with the center of the positive, then the extent of polarity in this covalent molecule is known as the dipole moment.
Dipole moment = magnitude of the charge x distance of separation
Dipole moment is a vector quantity and is represented by a small arrow with tail at the positive center and head pointing towards a negative center.
For example, the dipole moment of HCl molecule is 1.03 D and that of H2O is 1.84 D. The dipole of HCl may be represented as follows:
Dipole moment = magnitude of the charge x distance of separation
Dipole moment is a vector quantity and is represented by a small arrow with tail at the positive center and head pointing towards a negative center.
For example, the dipole moment of HCl molecule is 1.03 D and that of H2O is 1.84 D. The dipole of HCl may be represented as follows:
Tuesday, October 19, 2010
Ocean decomposers
Decomposers are living organisms that act as cleaner as they decompose the remains of plants and animals.They are mainly bacteria and fungi.
Since ocean occupies 70% of the Earth's surface, it has numerous number of ocean decomposers. According to depth and availability of sunlight and temperature, the ocean is divided into different zones and therefore, different types of decomposers are found in the ocean.
Some of the names of ocean decomposers are brittle stars, seagulls, sea slugs, sea worms and hagfish.
Since ocean occupies 70% of the Earth's surface, it has numerous number of ocean decomposers. According to depth and availability of sunlight and temperature, the ocean is divided into different zones and therefore, different types of decomposers are found in the ocean.
Some of the names of ocean decomposers are brittle stars, seagulls, sea slugs, sea worms and hagfish.
Reactivity series of metals
Reactivity series is an empirical series of metals in order of their reactivity from highest to lowest.
In the reactivity series of metals, going from bottom to top,1. the metals increase in reactivity 2.lose electrons more readily to form positive ions 3.corrode or tarnish more readily 4.require more energy (and different methods) to be separated from their ores 5.become stronger reducing agents.
The most active metal, potassium, is at the top of the list and the least reactive metal, gold, is at the bottom of the list.
The greater the ease with which an element loses its electrons and acquires a positive charge, the greater is its reactivity. Further, the greater the number of shells and lesser the number of valence electrons, the greater is the reactivity of the metal.
In the reactivity series of metals, going from bottom to top,1. the metals increase in reactivity 2.lose electrons more readily to form positive ions 3.corrode or tarnish more readily 4.require more energy (and different methods) to be separated from their ores 5.become stronger reducing agents.
The most active metal, potassium, is at the top of the list and the least reactive metal, gold, is at the bottom of the list.
The greater the ease with which an element loses its electrons and acquires a positive charge, the greater is its reactivity. Further, the greater the number of shells and lesser the number of valence electrons, the greater is the reactivity of the metal.
Natural resources
As the name suggests natural resources are resources that occurs naturally in our environments.Some of the examples of natural resources are coal, trees, natural gas, limestone, etc.
There are two types of natural resources:
1.Renewable resources:They can be reproduced easily. Sunlight, air, wind, etc., are continuously available and their quantity is not affected by human consumption.
2.Non-renewable resources:Minerals and fossil fuels take a long time to formed, so once exhausted by human consumption, its difficult to replenish.They are known as non-renewable resources.
On the basis of availability, natural resources can be categorized as exhaustible and non-exhaustible resources.Air and water are categorized as non-exhaustible since they are abundantly available.Coal and petroleum are examples of exhaustible natural resources.
There are two types of natural resources:
1.Renewable resources:They can be reproduced easily. Sunlight, air, wind, etc., are continuously available and their quantity is not affected by human consumption.
2.Non-renewable resources:Minerals and fossil fuels take a long time to formed, so once exhausted by human consumption, its difficult to replenish.They are known as non-renewable resources.
On the basis of availability, natural resources can be categorized as exhaustible and non-exhaustible resources.Air and water are categorized as non-exhaustible since they are abundantly available.Coal and petroleum are examples of exhaustible natural resources.
Corrosion of iron
What do you understand by corrosion of iron?
Corrosion of iron is also called rusted iron.Rusted iron is formed when iron is converted to iron oxide.It is formed when iron is in contact with water and oxygen.Rusted iron can also be formed because of the reaction of iron and chlorine in an environment deprived of oxygen.
Examples of rusted iron which are also called iron oxides are given as follows:
Hydrated iron(iii) oxide Fe2O3·nH2O and iron (iii) oxide-hydroxide Fe(OH)3).
In order to prevent corrosion of iron, galvanization method is used, i.e, layering the surface of iron with zinc.
Several other methods are also available for prevention of corrosion.
Corrosion of iron is also called rusted iron.Rusted iron is formed when iron is converted to iron oxide.It is formed when iron is in contact with water and oxygen.Rusted iron can also be formed because of the reaction of iron and chlorine in an environment deprived of oxygen.
Examples of rusted iron which are also called iron oxides are given as follows:
Hydrated iron(iii) oxide Fe2O3·nH2O and iron (iii) oxide-hydroxide Fe(OH)3).
In order to prevent corrosion of iron, galvanization method is used, i.e, layering the surface of iron with zinc.
Several other methods are also available for prevention of corrosion.
Momentum
What is momentum?
Object in motion is said to have momentum.Momentum has a size and direction and is a conserved quantity in physics.
The momentum formula is given as ;
P = mv, where p is the momentum of the moving object, m is the mass and v is the velocity.
From the formula we can say that momentum of a moving object is directly proportional to its mass and velocity.Momentum is classified as linear and angular momentum.
There are laws of conservation of momentum.We will learn about them with examples next time.
I hope you will find this article on momentum helpful.Please do post comments.
Object in motion is said to have momentum.Momentum has a size and direction and is a conserved quantity in physics.
The momentum formula is given as ;
P = mv, where p is the momentum of the moving object, m is the mass and v is the velocity.
From the formula we can say that momentum of a moving object is directly proportional to its mass and velocity.Momentum is classified as linear and angular momentum.
There are laws of conservation of momentum.We will learn about them with examples next time.
I hope you will find this article on momentum helpful.Please do post comments.
Properties of compounds
Let us first try to understand what are compounds before we discuss the properties of compounds.
A compound is a substance formed when two or more elements are chemically joined.
Some of the examples of compounds are sodium chloride, ferrous-oxide, etc.
Properties of compounds:
1.Compounds cannot be separated into its constituent elements by physical or mechanical means.
2.Properties of a compound and its constituents are very different.For example, carbon monoxide is compound of carbon and oxygen.Its is highly toxic to human beings and animals in high quantity whereas carbon and oxygen are not toxic.
2.A compound is a homogenous substance.
All compounds can exist as solid at low enough temperature.
A compound is a substance formed when two or more elements are chemically joined.
Some of the examples of compounds are sodium chloride, ferrous-oxide, etc.
Properties of compounds:
1.Compounds cannot be separated into its constituent elements by physical or mechanical means.
2.Properties of a compound and its constituents are very different.For example, carbon monoxide is compound of carbon and oxygen.Its is highly toxic to human beings and animals in high quantity whereas carbon and oxygen are not toxic.
2.A compound is a homogenous substance.
All compounds can exist as solid at low enough temperature.
Branches of chemistry
Chemistry is the science of matter and the changes it undergoes.It is concerned with the composition, behavior, structure, and properties of matter as well as the changes it undergoes during chemical reactions.
There are six branches of chemistry.
1.Organic chemistry
2.Inorganic chemistry
3.Physical chemistry
4.Analytical chemistry
5.Bio-chemistry
6.Nuclear chemistry.
Organic chemistry deals with organic compounds where as inorganic chemistry deals with inorganic compounds.Physical chemistry deals with atoms and sub-atomic particles.Analytical chemistry deals with analysis of the materials, be it natural or man-made.Bio-chemistry deals with the cells, their structures and composition.Nuclear chemistry deals with nuclear material and their radioactivity.
There are six branches of chemistry.
1.Organic chemistry
2.Inorganic chemistry
3.Physical chemistry
4.Analytical chemistry
5.Bio-chemistry
6.Nuclear chemistry.
Organic chemistry deals with organic compounds where as inorganic chemistry deals with inorganic compounds.Physical chemistry deals with atoms and sub-atomic particles.Analytical chemistry deals with analysis of the materials, be it natural or man-made.Bio-chemistry deals with the cells, their structures and composition.Nuclear chemistry deals with nuclear material and their radioactivity.
Monday, October 18, 2010
Properties of oxygen
Oxygen is indispensable for human beings and all living things both plants and animals.We use oxgygen for respiration.It has the chemical symbol as O2.
Properties of oxygen:
Physical properties:Oxygen is colorless, odorless and a tasteless diatomic gas under normal conditions.It is slightly heavier than air.Oxygen is sparingly soluble in water.
Chemical properties:Oxygen is combustible.All metals and non- metals react with oxygen to form their respective oxides.Oxygen oxidizes many compounds under suitable condition.
For example, hydrogen chloride gets oxidized to chlorine.
Because of its varied properties, oxygen is used for many purposes such as in steel making, for preparing oxygen containing organic compounds, such as ethylene oxide, phenol, etc. For medical purposes where O2 is required for emergency operations and respiratory.Oxygen is also used as an oxidizer in rocket propellants and in fuel cells.
Properties of oxygen:
Physical properties:Oxygen is colorless, odorless and a tasteless diatomic gas under normal conditions.It is slightly heavier than air.Oxygen is sparingly soluble in water.
Chemical properties:Oxygen is combustible.All metals and non- metals react with oxygen to form their respective oxides.Oxygen oxidizes many compounds under suitable condition.
For example, hydrogen chloride gets oxidized to chlorine.
Because of its varied properties, oxygen is used for many purposes such as in steel making, for preparing oxygen containing organic compounds, such as ethylene oxide, phenol, etc. For medical purposes where O2 is required for emergency operations and respiratory.Oxygen is also used as an oxidizer in rocket propellants and in fuel cells.
Propanone
Acetone is another name of propanone which is a highly inflammable liquid widely used as an organic solvent and as material for making plastics.
There are different ways of preparing acetone:
1.By dehydrogenation of propane-2-ol using heated copper.
2.By dry distillation of calcium acetate.
3.By Wacker Process.
Acetone is used as solvent in paints, varnishes and lacquers.It can remove the lustre from a textile for cellulose acetate fibres. It is used in the preparation of smokeless gun powder and unbreakable glass and for specification testing of vulcanised rubber products, as nail polish remover and to clean and dry parts of precision equipment.
There are different ways of preparing acetone:
1.By dehydrogenation of propane-2-ol using heated copper.
2.By dry distillation of calcium acetate.
3.By Wacker Process.
Acetone is used as solvent in paints, varnishes and lacquers.It can remove the lustre from a textile for cellulose acetate fibres. It is used in the preparation of smokeless gun powder and unbreakable glass and for specification testing of vulcanised rubber products, as nail polish remover and to clean and dry parts of precision equipment.
Law of conservation of momentum
The Law of Conservation of Momentum states that "If a group of bodies are exerting forces on each other, their total momentum remains the same before and after the interaction provided there is no external forces acting on them.
For example:
Two bodies A and B of masses m1 and m2 are moving in the same direction with initial velocities u1 and u2 . Suppose they collide each other. Let us assume that they continue moving in the same direction after collision.If the collision last for a very short interval of time 't' seconds.
During collision, A exerts a force on B. At the same time, B exerts a force on A. Due to these action and reaction forces the velocities of A and B get changed. After collision, let v1 and v2 be the velocities of the bodies A and B respectively.
i.e, m1v1-m1u1=-m2v2-m2u2
For example:
Two bodies A and B of masses m1 and m2 are moving in the same direction with initial velocities u1 and u2 . Suppose they collide each other. Let us assume that they continue moving in the same direction after collision.If the collision last for a very short interval of time 't' seconds.
During collision, A exerts a force on B. At the same time, B exerts a force on A. Due to these action and reaction forces the velocities of A and B get changed. After collision, let v1 and v2 be the velocities of the bodies A and B respectively.
i.e, m1v1-m1u1=-m2v2-m2u2
Covalent bond
Covalent bond is a form of chemical bonding that is characterized by sharing electrons between atoms.
Depending upon the number of shared electron pairs there are three types of covalent bonds - single, double and triple.
Covalent bond can polar covalent bond and non-polar covalent bond.
Covalent bond is said to be polar when the shared electrons move toward the atom with greater mass whereas in non-polar covalent bond, the shared electron pairs are at equal distance from both the atoms involved in bonding.
Example of non- polar covalent bond is Chlorine molecule and that of polar covalent bond is HCl
Depending upon the number of shared electron pairs there are three types of covalent bonds - single, double and triple.
Covalent bond can polar covalent bond and non-polar covalent bond.
Covalent bond is said to be polar when the shared electrons move toward the atom with greater mass whereas in non-polar covalent bond, the shared electron pairs are at equal distance from both the atoms involved in bonding.
Example of non- polar covalent bond is Chlorine molecule and that of polar covalent bond is HCl
Carbon
Carbons exist in nature as graphite and diamond.It exists in the form of carbon dioxide in the air.The major process by which carbon is brought into the living world is photosynthesis.Carbon is released back to the atmosphere through respiration.
Carbon cycle:It is the cycle by which carbon is brought in the earth and then released back to the atmosphere.
Carbon is mainly stored in the form of carbon-containing inorganic substances in the atmosphere or in the ocean as reservoir.Both consumers and producers in the ocean and the terrestrial environment can carry out respiration which releases carbon dioxide to the carbon reservoir in the ocean or in the atmosphere. Decomposers break down all organic materials and the remains of organisms. This releases the carbon stored into the reservoir through various metabolisms. When these organisms died, they were buried deep under the sea and the carbon inside was stored in sediments. After millions of years, because of the weathering of the sediments, the carbon can be released as dissolved carbon dioxide in the ocean again. Also these remains of aquatic organisms can turn into fossil fuels that we are using nowadays. The combustion of fossil fuels can release carbon to the atmosphere in the form of carbon dioxide as well.
Carbon cycle:It is the cycle by which carbon is brought in the earth and then released back to the atmosphere.
Types of bacteria
Bacteria are unicellular organism microorganisms.Based on how they how they process food, they are classified as autotrophic and heterotrophic bacteria.
Heterotrophic bacteria:These bacteria are not able to manufacture their own food, they depend on external source.They are further classified into three types:1.Saprophytic Bacteria 2.Symbiotic bacteria and parasitic bacteria.
Autotrophic bacteria: They are bacteria which can prepare their food themselves from inorganic substances like carbondioxide, hydroge and oxygen.Based on what kind of energy they use in preparing their food, they are again categorized as Photoautotrophic bacteria and Chemosynthetic bacteria.Photoautotrophic bacteria get energy from the sun.Chemosynthesis bacteria uses energy which is liberated from the oxidation of inorganic substances.
Heterotrophic bacteria:These bacteria are not able to manufacture their own food, they depend on external source.They are further classified into three types:1.Saprophytic Bacteria 2.Symbiotic bacteria and parasitic bacteria.
Autotrophic bacteria: They are bacteria which can prepare their food themselves from inorganic substances like carbondioxide, hydroge and oxygen.Based on what kind of energy they use in preparing their food, they are again categorized as Photoautotrophic bacteria and Chemosynthetic bacteria.Photoautotrophic bacteria get energy from the sun.Chemosynthesis bacteria uses energy which is liberated from the oxidation of inorganic substances.
Classification of alkanols
Alkanols are organic compounds with one hydroxyl functional group bound to a carbon group.
Classification of alkanols: According to the -OH group that is attached to a carbon atom which in turn is attached to 1, 2 or 3 carbon atoms respectively, alkanols are classified as primary, secondary and tertiary alkanol.
Examples of primary, secondary and tertiary alkanols are given below;
CH3CH2OH-Primary
Classification of alkanols: According to the -OH group that is attached to a carbon atom which in turn is attached to 1, 2 or 3 carbon atoms respectively, alkanols are classified as primary, secondary and tertiary alkanol.
Examples of primary, secondary and tertiary alkanols are given below;
CH3CH2OH-Primary
Properties of Metals
Metals are elements which have wide application in our daily life.Because of their properties they are used for many purposes.
The properties of metals are as follows:
1.Physical state- metals are solid at room temperature except mercury and gallium which are liquid at room temperature.
2.They are lustrous
3.They are malleable - they can be hammered and made into thin sheet.
4.They conduct electricity.
5.They are hard except potassium and sodium which are soft.
6.They have 1 to 3 electrons in their outermost shell of their atoms.
7.They are heavy and have high density.
8.They have high melting and boiling point.
9.They are electropositive in nature i.e, they give out electrons but do not accept electrons.
Because of these properties, they are used in computers, aerospace, construction, farming, etc.
The properties of metals are as follows:
1.Physical state- metals are solid at room temperature except mercury and gallium which are liquid at room temperature.
2.They are lustrous
3.They are malleable - they can be hammered and made into thin sheet.
4.They conduct electricity.
5.They are hard except potassium and sodium which are soft.
6.They have 1 to 3 electrons in their outermost shell of their atoms.
7.They are heavy and have high density.
8.They have high melting and boiling point.
9.They are electropositive in nature i.e, they give out electrons but do not accept electrons.
Because of these properties, they are used in computers, aerospace, construction, farming, etc.
Sunday, October 17, 2010
Reactivity of elements
Elements are the smallest substances that exist.They react each other to form molecules and compounds.
The reactivity of elements is determined by their dissociation energy and electron affinity.
Among the elements, halogens are the most reactive elements due to their low dissociation energy and high electron affinity value.Florine is the most reactive element due to weak bond between florine atoms because of strong repulsion between the non-bonding electrons.Florine, chlorine, bromine, iodine, hydrogen, oxygen and nitrogen are called halogen group.
You can learn the reactivity of elements from Reactivity series which is a summarized information about the reactivity of all element.It is by these reactivities that chemical reactions take place.
The reactivity of elements is determined by their dissociation energy and electron affinity.
Among the elements, halogens are the most reactive elements due to their low dissociation energy and high electron affinity value.Florine is the most reactive element due to weak bond between florine atoms because of strong repulsion between the non-bonding electrons.Florine, chlorine, bromine, iodine, hydrogen, oxygen and nitrogen are called halogen group.
You can learn the reactivity of elements from Reactivity series which is a summarized information about the reactivity of all element.It is by these reactivities that chemical reactions take place.
Nutrition in plants
Nutrition may be defined as the process obtaining food to support life.Plants use minerals as their food.
Plants absorb minerals from soils.So, fertility which means the capability of soil to provide nutrients to
plants determine the healthy growth of plants.
Most of the plants are autotrophic.Autotrophs are those that utilize carbon dioxide as their sole provider of carbon.Nutrition in plants is supported by sun through the process called photosynthesis.For example carbohydrate which is the main source of energy is obtained by using carbon, hydrogen and oxgygen
through the process photosynthesis.
The study of how plant get mineral to prepare food is known as mineral nutrition.
If plants do not get sufficient nutrients, specific symptoms appear due to deficiency
of a particular mineral.
There are some methods of supplying nutrients to plants for a healthy growth.
These methods are very helpful for good a harvest.use of fertilizers is one example of providing
nutrients to plants.
Plants absorb minerals from soils.So, fertility which means the capability of soil to provide nutrients to
plants determine the healthy growth of plants.
Most of the plants are autotrophic.Autotrophs are those that utilize carbon dioxide as their sole provider of carbon.Nutrition in plants is supported by sun through the process called photosynthesis.For example carbohydrate which is the main source of energy is obtained by using carbon, hydrogen and oxgygen
through the process photosynthesis.
The study of how plant get mineral to prepare food is known as mineral nutrition.
If plants do not get sufficient nutrients, specific symptoms appear due to deficiency
of a particular mineral.
There are some methods of supplying nutrients to plants for a healthy growth.
These methods are very helpful for good a harvest.use of fertilizers is one example of providing
nutrients to plants.
Chemistry problems
I hope this article will help you in understanding the basic concepts of Chemistry.The Chemistry problems you are facing will be solved if you know if you know what chemistry is all about.
Let me define "What is Chemistry?"
Chemistry is the science of matter and energy and the interaction between them.
Matter is anything that exist in mass.The smallest substances that exist in the earth are elements.
In Chemistry you will learn about how elements interact to form atoms and molecules, how compounds are formed.For example, water H2O is formed by two atoms of hydrogen and one atom of oxygen.In nature positive and negative charges attract each other, some atoms have negative charges and some positive charges.According to free charges available in an atom and charges needed by another atom, interactions are taken place to stabilize the atoms that are not stable.So, in order to stabilize an om chemical bonding takes place.
Next time we will learn about Chemical bonding in detail.
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Let me define "What is Chemistry?"
Chemistry is the science of matter and energy and the interaction between them.
Matter is anything that exist in mass.The smallest substances that exist in the earth are elements.
In Chemistry you will learn about how elements interact to form atoms and molecules, how compounds are formed.For example, water H2O is formed by two atoms of hydrogen and one atom of oxygen.In nature positive and negative charges attract each other, some atoms have negative charges and some positive charges.According to free charges available in an atom and charges needed by another atom, interactions are taken place to stabilize the atoms that are not stable.So, in order to stabilize an om chemical bonding takes place.
Next time we will learn about Chemical bonding in detail.
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Friday, October 15, 2010
Biology
What is Biology?
Biology is the science of living beings including their structure, function, growth, origin, evolution, distribution, and taxonomy.
Importance of biology: Biology is is very important for our daily lives.
Agriculture which is the basic activities of human being depend on Biology. It is through the study
of plants and the basic principle which is followed by them in preparing food.It studies what all are
required for a healthy growth of plants.
By advancing in science,human health and well-being are improved.Scientists have discovered how to prevent diseases by developing vaccines.
You will find most of the time in newspapers or science magazines the recent development in
how to fight against cancers and many incurable diseases.
Biology is the science of living beings including their structure, function, growth, origin, evolution, distribution, and taxonomy.
Importance of biology: Biology is is very important for our daily lives.
Agriculture which is the basic activities of human being depend on Biology. It is through the study
of plants and the basic principle which is followed by them in preparing food.It studies what all are
required for a healthy growth of plants.
By advancing in science,human health and well-being are improved.Scientists have discovered how to prevent diseases by developing vaccines.
You will find most of the time in newspapers or science magazines the recent development in
how to fight against cancers and many incurable diseases.
Uses of nitrogen
Nitrogen is one of the elements that exist the earth.Many industrial compounds contains nitrogen.
Ammonia, nitric acids and cyanides contain nitogen.
Uses of Nitogen:1. Nitrogen is used in beer by mixing with carbon to maintain the saturation of beer
with carbondioxide.
2.Liquid nitogen used as an refrigerant.
3. Some nitrogen compounds are used as fertilizer.
Nitrogen is found as gas in the atmosphere.It enters into living organism through lightning.It is converted into biologically useful compounds through lightning.
Ammonia, nitric acids and cyanides contain nitogen.
Uses of Nitogen:1. Nitrogen is used in beer by mixing with carbon to maintain the saturation of beer
with carbondioxide.
2.Liquid nitogen used as an refrigerant.
3. Some nitrogen compounds are used as fertilizer.
Nitrogen is found as gas in the atmosphere.It enters into living organism through lightning.It is converted into biologically useful compounds through lightning.
Types of carbohydrates
Carbohydrates are found mostly in rice.It is an organic compound of carbon, oxygen and hydrogen.
Most food contain carbohydrates.
Carbohydrates in food are broken down into simple sugars.The main function of carbohydrates is
to provide energy to the body.
Carbohydrates are of two types:
1.Simple carbohydrates and 2.Complex carbohydrates.
Simple carbohydrates are also called sugars.Complex carbohydrates include fibers and starches.
Carbohydrates are nothing , you are seeing with your eyes everyday whenever you eat your meal.You can find it in fruits as well.
Most food contain carbohydrates.
Carbohydrates in food are broken down into simple sugars.The main function of carbohydrates is
to provide energy to the body.
Carbohydrates are of two types:
1.Simple carbohydrates and 2.Complex carbohydrates.
Simple carbohydrates are also called sugars.Complex carbohydrates include fibers and starches.
Carbohydrates are nothing , you are seeing with your eyes everyday whenever you eat your meal.You can find it in fruits as well.
Types of nerves
Nerves are like small wires found in the body.The nerves cells are also called neurons.
Most of the nerves are associated to the middle nervous system through the spinal cord.
There are two types of nerves:
1.Afferent nerves
2.Efferent nerves
Afferent nerves and efferent nerves have different functions.Afferent nerves take messages from to the brain from the body.Efferent nerves take messages from the brain to the body.
There are billions of nerves cell in human body.
Most of the nerves are associated to the middle nervous system through the spinal cord.
There are two types of nerves:
1.Afferent nerves
2.Efferent nerves
Afferent nerves and efferent nerves have different functions.Afferent nerves take messages from to the brain from the body.Efferent nerves take messages from the brain to the body.
There are billions of nerves cell in human body.
Ecosystem
Ecosystem is a functional unit that consist of living things and non-living things in a given area, linked together through nutrient cycle and energy flow.
There are two types of ecosystem:
1.Terrestrial ecosystem and 2.Aquatic ecosystem.
Terrestrial ecosystem exists on land and aquatic ecosystem exists in water.
Ecosystem give important life-support services to human beings.Both types of ecosystem have been affected by human activities.Water pollution from industries and deforestation may be given as examples.
There are two types of ecosystem:
1.Terrestrial ecosystem and 2.Aquatic ecosystem.
Terrestrial ecosystem exists on land and aquatic ecosystem exists in water.
Ecosystem give important life-support services to human beings.Both types of ecosystem have been affected by human activities.Water pollution from industries and deforestation may be given as examples.
Mutation in living organism
Before we discuss mutation in living organism let us first try to understand what is mutation.
Mutation is a permanent change in the DNA of a gene.It causes an alteration in the sequence of the amino acids of the protein..
Mutation are not life threatening.Many people undergo mutation and still lead a healthy life.
Mutation is done for plants as well.
To know more about mutation both in plants and animals, you can check in internet where you can find
helpful information.
Mutation is a permanent change in the DNA of a gene.It causes an alteration in the sequence of the amino acids of the protein..
Mutation are not life threatening.Many people undergo mutation and still lead a healthy life.
Mutation is done for plants as well.
To know more about mutation both in plants and animals, you can check in internet where you can find
helpful information.
Thursday, October 14, 2010
Whorls of Hibiscus flower
Hibiscus is a shrub which belongs to the family Malvaceae.The Hibiscus flower grows from the axil of a leaf like structure.Hibiscus flower is a bisexual flower as it has both male and female reproductive part in the same flower.
There are four whorls in a typical Hibiscus flower.They are calyx,corolla,androecium and gynoecium.
Calys:It is made up of sepals.Five sepals are united together to form a cup like structure which is called gamosepalous.Calyx protect the flower in the bud stage.
Corolla-It is made up five petals which are in free condition.The petals are brightly coloured to attract the insects for pollination.
Androecium-It is the male reproductive part. Androecium in Hibiscus consist of anther and filament.Inside the anther they contains pollengrains which contains the male gametes..They produce numerous stamens and the filaments of all the stamens are united to form a single bundle and such a condition is called monadelphous.
Gynoecium-It is the female reproductive part.It consist of ovary,style and stigma.Hibiscus flower consist of 5 carpels which are united.The ovules are developed on the placenta at the central axis of the septa.
Hibiscus flower contain all the floral whorls.So, it is also known as a complete flower.
There are four whorls in a typical Hibiscus flower.They are calyx,corolla,androecium and gynoecium.
Calys:It is made up of sepals.Five sepals are united together to form a cup like structure which is called gamosepalous.Calyx protect the flower in the bud stage.
Corolla-It is made up five petals which are in free condition.The petals are brightly coloured to attract the insects for pollination.
Androecium-It is the male reproductive part. Androecium in Hibiscus consist of anther and filament.Inside the anther they contains pollengrains which contains the male gametes..They produce numerous stamens and the filaments of all the stamens are united to form a single bundle and such a condition is called monadelphous.
Gynoecium-It is the female reproductive part.It consist of ovary,style and stigma.Hibiscus flower consist of 5 carpels which are united.The ovules are developed on the placenta at the central axis of the septa.
Hibiscus flower contain all the floral whorls.So, it is also known as a complete flower.
The natural system classification
Carolus Linnaeus classification of natural system is one of the earliest classification.His classification is known as the" Two Kingdom Classification".In this classification all the living organisms are placed under two categories.Here plants and animals are divided.
Plants are placed under "Kingdom Plantae" and animals are placed under "Kingdom Animalia".So Animalia is the name given to animal kingdom.Kingdom Animalia includes the animals such as protozoans, sponges, jelly fishes, worms, crabs, insects, spiders, snails, starfishes, sharks, bony fishes, frogs, lizards, birds and mammals.
Animal kingdom was initially divided into unicellular and multicellular. Protozoa is unicellular and metazoa is multicellular.Metazoa is further divided into vertebrates and invertebrates.
Plants are placed under "Kingdom Plantae" and animals are placed under "Kingdom Animalia".So Animalia is the name given to animal kingdom.Kingdom Animalia includes the animals such as protozoans, sponges, jelly fishes, worms, crabs, insects, spiders, snails, starfishes, sharks, bony fishes, frogs, lizards, birds and mammals.
Animal kingdom was initially divided into unicellular and multicellular. Protozoa is unicellular and metazoa is multicellular.Metazoa is further divided into vertebrates and invertebrates.
Elements
Before we can proceed to learn what are elements, it is important to know what is matter.Matter is any substance that has mass.Matter is classified into two categories: Pure substances and mixture.
Pure substances are made up of only one element whereas a mixture is a material containing two or more elements or compounds that are in close contact and are mixed in any proportion. The components of mixtures can be separated by physical means.
Elements come under pure substances.They are the smallest matters that exist on earth.It cannot be further divided into simpler substances by ordinary processes. Oxygen and hydrogen are one of them.There are 114 elements found out of which 92 of them occur in nature.Elements are also sub-divided into metal and non-metal.Iron is an example of metal and sulphur is is an example of non-metal.
Elements are the basic building of every object or things that exist on Earth.Water is formed from oxygen and hydrogen.Forming process may vary but everything has element in it.
Next time i will share with you a learning on general chemical.
Pure substances are made up of only one element whereas a mixture is a material containing two or more elements or compounds that are in close contact and are mixed in any proportion. The components of mixtures can be separated by physical means.
Elements come under pure substances.They are the smallest matters that exist on earth.It cannot be further divided into simpler substances by ordinary processes. Oxygen and hydrogen are one of them.There are 114 elements found out of which 92 of them occur in nature.Elements are also sub-divided into metal and non-metal.Iron is an example of metal and sulphur is is an example of non-metal.
Elements are the basic building of every object or things that exist on Earth.Water is formed from oxygen and hydrogen.Forming process may vary but everything has element in it.
Next time i will share with you a learning on general chemical.
Wednesday, October 13, 2010
Organ systems of the human body
Human body consists of ten major organ systems that work together as a unit.There are several smaller organs that are associated with each of the major organ systems of the human body.
The ten major organ systems of the human body have their own function.All the functions are interrelated.If the function of one organ system fails, the functions of other organ systems are affected.The major organ systems are describe below:
1)Circulatory organ system
2)Digestive:Organs in the digestive system includes mouth, stomach, intestine, rectum, teeth, tongue, liver and pancreas.
3)Endocrine
4)Integumentary
5)Muscular
6)Nervous
7)Reproductive
8)Respiratory
9)Skeletal
10)Urinary/Excretory
Among the organ systems of the human body integumentary organ system is the largest organ.
The ten major organ systems of the human body have their own function.All the functions are interrelated.If the function of one organ system fails, the functions of other organ systems are affected.The major organ systems are describe below:
1)Circulatory organ system
2)Digestive:Organs in the digestive system includes mouth, stomach, intestine, rectum, teeth, tongue, liver and pancreas.
3)Endocrine
4)Integumentary
5)Muscular
6)Nervous
7)Reproductive
8)Respiratory
9)Skeletal
10)Urinary/Excretory
Among the organ systems of the human body integumentary organ system is the largest organ.
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