Inside the Atom

Inside the Atom

• Over 2000 years ago the Greeks gave the name “atom” to what they believed must be the smallest piece of matter.

• Since then, great scientists such as Dalton, Thomson, Rutherford, and Bohr developed this theory into a current theory on the atom.

There are three parts that make up the atom:

• Protons

• Neutrons

• Electrons

Protons

• positively charged particles,

• located in the nucleus,

• number of protons equals the Atomic Number

• Protons have a mass of one atomic mass unit (amu)

Neutrons

• particles have no charge,

• located in the nucleus,

• number of neutrons plus protons equals the Mass Number

• Neutrons have a mass of one atomic mass unit (amu)

Electrons

• negatively charged particles,

• located in orbit around the nucleus in different energy levels

• It takes about 1,836 electrons to equal the mass of one proton