What is Matter?

Matter is anything that has mass. All objects are made of matter. Air, water, a brick, even

you are made of matter!

Matter is made up of smaller pieces.

Over eighty years ago, scientists thought that the atom was the smallest piece of matter.

At that time, the atom was thought to be Ôthe building block of matter.Õ

In 1911, a scientist named Ernest Rutherford discovered that atoms are really made of a

positively charged center called the nucleus orbited by negatively charged particles called

In 1911, a scientist named Ernest Rutherford discovered that atoms are really made of a

positively charged center called the nucleus orbited by negatively charged particles called

electrons.

In 1932, scientists discovered that the nucleus of an atom is made of smaller particles called

protons and neutrons. Protons carry a positive charge while neutrons have no charge at all.

Protons and neutrons are each called nucleons since they are found in the nucleus. When they

were discovered, scientists thought they were the smallest piece of matter

 

As scientists did more experiments, they began to realize that there was something funny

about protons and neutrons. In 1968 they discovered that protons and neutrons are made up of

smaller particles they called quarks. Scientists discovered six different types of quarks: Up,

Down, Strange, Charm, Top and Bottom. Protons have two Up quarks and one Down quark

while neutrons have two Down quarks and one Up quark. Quarks are held to each other by

particles scientists called gluons.

Some scientists now think that the quark is the smallest piece of matter. Scientists used to

think that atoms were the smallest bit of matter, but they discovered that it was not. Do you

think that the quark is the smallest piece of matter or do you think that there might be

something smaller inside the quark?