1. Subatomic Particles

2. Charge A proton has a positive (+1) electric charge.
Neutrons have no electric charge. They are neutral.
Electrons have a negative (−1) electric charge.

3. Relative size A proton’s relative mass is 1.007 amu
A neutron’s relative mass is amu
An electron’s relative mass is

4. Atomic Number
The number of protons in the nucleus of an atom determines the atomic number of the element.

5. Atomic Mass Number
The number of protons plus the number of neutrons in the nucleus of an atom equals the atomic mass number.

6. Electrons
In a stable atom (not an ion) the number of electrons equals the number of protons in the nucleus.
Electrons are set in "orbits" or shells around the nucleus. Another view is that they form a cloud around the nucleus.

7. Yellow- Beryllium (Be)
Green- Fluorine (F)
Blue- Boron (B)
Black- Lithium (Li)
Red- Sodium (Na)

8. Isotopes
In a different isotope of an atom, the number of neutrons and atomic mass differ. Number of protons and electrons stays the same.
When you see “Oxygen-17” or “Oxygen-18”, the number is referring to the atomic mass.
How many protons, neutrons, and electrons does Oxygen- 18 have?

9. How many protons, neutrons, and electrons are in each isotope?