1. ATOMS AND ATOMIC STRUCTURE Atom Nucleus Proton Neutron Electron

2. WHAT IS AN ATOM? The smallest unit of an element.
Consists of a central nucleus surrounded by one or more electrons.

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

4. WHAT IS A PROTON? Positively charged particle.
Found within an atomic nucleus.
Relatively large

5. WHAT IS A NEUTRON?
Uncharged particle.
Found within an atomic nucleus.

6. WHAT IS AN ELECTRON? Negatively charged particle.
Located in shells that surround an atom's nucleus.
VERY small

7. What makes up the atom? Nucleus Orbitals Protons (positive)
Neutrons (no charge)
Orbitals
Electrons (negative)
Fill starting with the innermost orbital
Outermost orbital is called the valance shell.
Electrons in valance shell are called valance electrons.

8. How to read the periodic table?
Potassium K
Name of Element
Atomic Number
Atomic Symbol
Atomic Mass/ Weight
(Mass Number)

9. How to read the periodic table?
Potassium K
Name of Element
Atomic Number – this is the number of protons in the nucleus. Since the overall charge of the atom is neutral, there is one electron for each proton.
Atomic Symbol
Atomic Mass (Weight)
This number represents the number of protons plus the number of neutrons in the nucleus.

10. How to calculate what makes up an atom?
Answers:
Atomic Mass = 39
Atomic Number = 19
Protons = 19
Electrons = 19
Neutrons = 20
Potassium K
Atomic Number
Atomic Mass/ Weight
(Round to the nearest whole number when using in calculations)
How to calculate Protons, Neutrons, and Electrons:
# Protons = Atomic Number
# Electrons = # Protons in a neutral atom
# Neutrons = Atomic Mass (rounded) – Atomic Number
You try Potassium…….

11. Let’s do an example Element = Carbon Atomic mass = 12
Atomic number = 6
Protons = ?
Neutrons = ?
Electrons = ?
Element = Carbon
Atomic mass = 12
Atomic number = 6
Protons = 6
Neutrons = 6
Electrons = 6