Atomic number

The number of proton in an atom is called its atomic number.

The name of an atom also depend on the atomic number.

The atom which has one proton is known as Hydrogen.

Hydrogen atom with one proton

The atom which contain eight proton is known as Oxygen.


In Nature an atom can contain maximum 92 proton which is known as Uranium.
( Atomic number more than 92 can make only in the laboratory)


Adding one proton into the center of hydrogen atom will change its name to Helium, so be careful!!
if you add two proton into the hydrogen atom then the name will change to Lithium.

States of Matter

There are three important states of matter,

1. Gaseous
2. Liquid
3. Solid
In addition, there are the liquid crystalline states and the plasma state.

For example, at room temperature, the water is in liquid state.On heating it changes into water vapor; when cooled, it solidifies to ice. All these changes are physical changes.


                                          Water at gaseous state is known as water vapor.

On heating Water changes into Water vapor


In gaseous state the molecules in least ordered state. the molecules are separated each other by large distance. 

                                                   Water at liquid state is known as water.

On cooling Water vapor changes into Water

In liquid state, the molecules are not very closely packed as in solid, they can  move somewhat freely.

                                                     Water at solid state is known as ice.

When cooled again water solidifies to ice

In a solid state, the molecules are closely packed, they posses  definite  shape  , size  and  volume.

Matter

Matter is composed of small particle. Matter exist in different state due to the attraction and repulsion among its small particles depending upon temperature and pressure.

Everything which have existence is matter

Every hardware of your computer is matter but software are not matters.
Your body is composed of many particles. These are matters.
Your dream is not made by matter.
Software have existence, why it is not a matter?
Matter have mass, can you calculate the mass of software?

What is Chemistry?

Different definition are given about chemistry

1. Chemistry is the knowledge about the chemicals.
2. Chemistry is the knowledge of particles.
3. Chemistry is the researched based knowledge of every matter.
4.  Chemistry, a branch of physical science, is the study of the composition, properties and behavior of matter.
5.  chemistry is the study of matter and the changes it can undergo
6.  Chemistry is a branch of natural science that deals principally with the properties of substances, the changes they undergo।