1. Intro to Atomic Structure
The Atom
Intro to Atomic Structure

2. Atom: the smallest particle that can still be considered
The Modern Model
At the center of the atom is a tiny, dense nucleus that contains protons and neutrons. Surrounding the nucleus is a cloudlike region of electrons that are constantly moving in energy levels.
Atom: the smallest particle that can still be considered
an element

3. The Atom is made up of Particles “Subatomic Particles”
Symbol
Charge
Mass
Location
Proton p+ +
1 amu
Nucleus
Neutron n
Electron e- -
amu
Cloud
(Energy Levels)

4. Important Facts
Almost all the mass of an atom is concentrated in the nucleus
The Atomic Number is equal to the # of protons
The # of protons is equal to the # of electrons ( p+ = e- )
The Atomic Mass is equal to the sum of protons and neutrons
Atoms of an element that have the same # of protons, but a different # of neutrons are called Isotopes.

5. 1 Carbon Atom