1. Unit 3A – SFMS Rebecca Collins
Atomic Structure
Unit 3A – SFMS Rebecca Collins

2. Parts of an Atom
Nucleus – cluster in the center of an atom that is positively charged containing protons and neutrons
Protons – positively charged atomic particles – large portion of atomic mass
Neutrons – atomic particles with no charge, only function to add mass to atom.
Electrons – very tiny, negatively charged particles that orbit the nucleus of an atom
Orbit because they are attracted to the nucleus’ positive charge like a magnet

3. Atomic Number
Atomic Number – the unique number of protons in the nucleus of an atom for a specific element
Example – Carbon has 6 protons – atomic number is 6
Example – Oxygen has 8 protons – atomic number is 8