What is Matter?

 

Matter is anything that occupies space, has mass and weight.

            Big objects occupy more space than small ones.

 

Mass is the amount of material in an object.

Weight is the measure of the pull of gravity on an object.

            Mass remains the same no matter where the object is.

Weight varies depending on the place of the object on earth and in other heavenly bodies.

 

All matter are made up of small particles.  Each particle is called a molecule.

Other forms of matter can also be broken into molecules.

 

Molecule, from a Latin word which means “a little quantity”, is still made of very small particles called atoms.

 

The word atom comes from the Greek word atomos which means “uncut or cannot be divided.”

 

An atom is the basic unit of all matter.  Atoms are so small that even some powerful microscopes are not strong enough to view them.

 

Many scientists had been wondering about atoms.  In the early 1800s, an English chemist and physicist named John Dalton proposed that atoms were solid particles that could not be divided.

 

In 1897, a British physicist named  Joseph John Thomson discovered smaller particles which move around the nucleus in a path called orbit.  Electrons have negative (-) electrical charge.

 

In 1919, Sir Ernest Rutherford, a British scientist, tested Thomson’s model and discovered small particles inside the nucleus which he called protons.  They have positive (+) charge.

 

In 1932, another British scientist, Sir James Chadwick, discovered a particle with neutral charge called neutron.  The proton and neutron from the nucleus.

 

In 1913, a Danish physicist named Niels Bohr saw the atom as a small solar system with its nucleus as the sun and the electrons revolving around it as planets orbiting the sun.

 

Some scientist, however, state that the electrons form a cloud around the nucleus.

 

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