Counting Protons Neutrons Electrons

Squares of the Periodic Table

• Atomic Number

– (# of protons)

• Symbol
• Name
• Atomic Mass

– (protons + neutrons)

Atomic Number

• Number of protons is also the number of electrons

• Each element has

different atomic number

Calculating neutrons

• If protons + neutrons =

atomic mass

• Then atomic mass –

protons = neutrons

Calculating neutrons practice

• Atomic Mass=37
• Atomic Number =17
• # of Neutrons =

Atomic Mass=35
Atomic Number =17
# of Neutrons =

​M - A = N