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 apositively 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
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 theywere 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?