1. What Are Elements?

2. Elements
An element is a substance that cannot be broken down into simpler substances by physical or chemical means
92 elements occur naturally on earth and in stars
Others are produced in labs
Each element has it’s own symbol
Ex.) H stands for hydrogen

3. Chemical Symbol
Atomic Number
Atomic Mass

4. Elements are Made of Atoms
Particle
Where found
Charge
Mass
Electron
Outside nucleus
negative
Hardly any
Proton
In nucleus
positive 1
Neutron
neutral
An atom is the smallest particle of an element that has all of it’s characteristics of that element
Atoms consist of even smaller parts
Proton, neutron, and electrons
A nucleus of an atom is made up of protons and neutrons

5. Equations
The number of protons in an atom’s nucleus is the atomic number
# of protons + # of neutrons = mass number
Atoms have a neutral charge because they have the same number of electrons and protons