1. STRUCTURE OF THE ATOM

2. 1.What are subatomic particles?
Particles smaller than an atom.
2. What makes up subatomic particles?
Quarks.
3. What are the 3 main subatomic particles composing the atom?
Neutron, Proton, and Electrons
4. What is the nucleus of the atom?
The nucleus in the core of the atom located in the center of the atom.

3. SUBATOMIC PARTICLES LOCATED ON THE NUCLEUS
Proton
Are positively charged particles found in the nucleus. All Protons are identical regardless of the element in which they are found. The mass of a proton is 1 amu.

4. NEUTRONS
Neutrons have no charge. All Neutrons are identical. Neutrons have slightly more mass than protons. The mass of a neutron is 1 amu(Atomic Mass Unit)

5. Subatomic Particle Located Outside of the Nucleus
Electron
Electrons have a negative charge. They do not move in a fixed path. Electrons are found in the Electron Cloud –the space in an atom outside the nucleus. Electrons are arranged in Energy Levels. An Energy Level is the most likely location in the electron Cloud in which an electron can be found.

6. 5. What is Atomic Number?
The number of protons in the nucleus of an atom.
6. What is Mass Number?
The sum of the protons and the neutrons in the nucleus.
To calculate number of neutrons:
Neutrons = Atomic Mass-Protons.

7. 7.What is an Isotope?
When atoms of the same element have the same number of protons but a different number of neutrons.

8. 8.What is Atomic Mass?
The average mass of all the isotopes of that element as they occur in nature.