Welcome to Matter Anything which occupies space and has mass is called Matter.
Matter exists in 3 states-Solid,Liquid and Gas.
Solids have a definite shape and volume. Liquids have a definite volume but takes the shape of the container.Gassas does not have any shape or volume.Solids cannot be compressed because there is no intermolecular space.Liquids can be compressed slightly because there a little space between the molecules.Gasses can be compressed very easily because there is lot of space between the molecules.
Any pure substance whose molecules contain same type of atom is called elements
the smallest unit of pure substance which exist independently and can have all the physical & chemical properties of that particular substance is called as a molecule.
Classification of Elements
Elements are divided into three classes (1) Metals (2) Non-Metals (3)Noble Gasses
Metals~Any element is a metal if it has the following characterstics.
It has lusture or shine.It is good conducter of heat or electricity.Is ductile(can be drawn into wires).Is malleable(Can be made into sheets).Is a solid at room temperature.Note~Mercury is liquid at room temperature.It has high melting point and boiling point.
Non metal~The element is non metal if it has the following characterstics.
It has no lusture.It is a bad conducter of heat and electricity.It is not ductile.It is not malleble.It is a gas or liquid or brittle solid at room temperature.
Noble gasses~The element which are found in very small quantity is gaseous state,which do not react chemically with any other element are called Nole gasses.They are also called rare gasses.Example~He,Ne,Ar,Kr,Xe,Rn.etc.
Compound
When the molecule of a sustance contain 2 or more atoms of different element comined together in a definite ratio.Then it is said to be a compound.
A compound cannot be seperated or broken down into its elements by physical means.It can be broken down chemically.
Mixtures
If 2 or more substances are mixed together in any propotion with out under going any chemical reaction.It is called Mixture.
There are two kinds of mixture.
Heterogenious Mixture~A mixture in which its constituents are not distributed uniform is called Heterogenious mixture.
Homogenious Mixture~A mixture in which 2 or more substances are evenly distributed through out mixture.
Chemical Formula
The representation of one molecule of a substance in the form of symbols is called Chemical Formula.
Atomicity
The number of atoms present in 1molecule of a element is called atomicity.
The elements which have one atom in their molecule are called monoatomic. The molecules of oxygen has 2 atom in it ,such elements are called diatomic.Some elements have more than 2 atoms in it .They are called Polyatomic.
The no. of hydrogen atoms which combind directly or indirectly with 1 atom of an element so as to form a chemical compound is called its vallency.In the molecule of ammonia NH3 one atom of nitrogen combins with 3 atoms of hydrogen .Therefore vallency of hydrogen is-3 .Since it is a nonmetal.
Chemical Equation
Representing a chemical reaction in a very short form using symbols is called Chemical Equation.
C+o2=CO2
Fe+S=FeS
Mg+O=Mgo
