Chapter 2

In this unit we need to be familiar with this type of symbol

Includes an element name a ‘-’ and a number◦ Example: Sulfur – 32◦ This sulfur atom has an atomic mass of 32◦ Since Sulfur has ______ protons & electrons◦ It also has ______ neutrons

Particle Symbol Charge Mass (amu) Location

Proton

Neutron

Electron

Calculate the average atomic mass of magnesium given the following information:

Mg, mass = 23.98 amu; percent abundance = 78.99%

Mg, mass = 24.98 amu; percent abundance = 10.00%

Mg, mass = 25.98 amu; percent abundance = 11.01%