The document reviews the basic structure of an atom, including the nucleus which is at the center and contains protons and neutrons, protons which are positively charged particles in the nucleus, neutrons which are uncharged particles in the nucleus, and electrons which are negatively charged particles that surround the nucleus in shells. It prompts the reader to recall what they know about these components before continuing to define each part in more detail.

1. Let’s Review the STRUCTURE
OF AN ATOM

2. Let’s review the parts of an atom,
then draw we will draw and label
our own!
o Before we continue, in 1 minute, write down everything you can
remember about the following items.
Nucleus
Proton
Neutron
Electron
Valence electron
Shells

3. WHAT IS THE NUCLEUS?
o The central (middle)
part of an atom.
o Composed of protons
and neutrons.
o Contains most of an
atom's mass. Why?

4. WHAT IS A PROTON?
o Positively charged
particle.
o Found within an
atomic nucleus.
o Same as the ATOMIC
NUMBER

5. WHAT IS A NEUTRON?
o Uncharged (neutral)
particle.
o Found within an
atomic nucleus.

6. WHAT IS AN ELECTRON?
o Negatively charged
particle.
o Located in shells that
surround an atom's
nucleus.
o Much smaller than
protons and neutrons