Elements
Unique substances that can’t be broken down into simpler substances
Matter
Takes up space and has mass
Carbon
C
6
Oxygen
O
8
Hydrogen
H
1
Nitrogen
N
Calcium
Ca
Sulfur
S
Sodium
Na
Phosphorus
P
Potassium
K
Magnesium
Mg
Iron
Fe
Chlorine
Cl
Atomic number
Number of protons
Atomic mass
Protons+neutrons
Atomic weight
Average of the mass numbers of all the isotopes in an element
Isotope
Element with varying number of neutrons
Radioactive
Process of spontaneous atomic decay, energy is emitted from the nucleus
Molecule
Two or more atoms bonded together
Compound
Two or more elements bonded together
Ion
Charged atom
Valence shell
Electrons outer shell that participates in chemical bonding
Ionic bond
Electrons are donated or taken