Reading the Periodic Table

What does Atomic Mass tell us?

QUESTION…How could you find the number

of neutrons???

Answer:

Atomic #

# of neutrons

Atomic mass (rounded)

Lets give it a Try!

How many protons, electrons, and neutrons does Ne have?

10 p+

10 e-

10 n0

Let’s Practice…

Find the number of p+, e-, and n for each element:

1. H 2. He 3. Tb

1 p+ 2 p+ 65 p+

1 e- 2 e- 65 e-

0 n 2 n 94 n

Class Work…Find the number of p+, e-, and n for each

element:

1. Si2. Hg3. Fe4. Ta5. Pt

• Protons (+): Atomic Number

• Neutrons: Atomic Mass minus Protons

• Electrons (-): Same number as Protons

• Protons (+): Atomic Number

• Neutrons: Atomic Mass minus Protons

• Electrons (-): Same number as Protons

• Protons (+): Atomic Number

• Neutrons: Atomic Mass minus Protons

• Electrons (-): Same number as Protons

Atomic Particles

ParticleParticle LocationLocationMass inMass in

amuamuChargeCharge

ProtonProton

NeutronNeutron

ElectronElectron

Atomic Particles

ParticleParticle LocationLocationMass inMass in

amuamuChargeCharge

ProtonProton

NeutronNeutron

ElectronElectron

What is amu????• amu is short for atomic mass unit

•

Atomic Particles

ParticleParticle LocationLocationMass inMass in

amuamuChargeCharge

ProtonProton

NeutronNeutron

ElectronElectron

Nucleus

Nucleus

Cloud

1

1

0

+1

-1

0

Atomic Inventory

ElementElement SymbolSymbol AtomicAtomic

NumberNumber

Mass Mass NumberNumber

ProtonsProtons NeutronsNeutrons ElectronsElectrons

He

Mg

Fe

Ar

2

12

26

18

4

24

56

40

2

12

26

18

2

12

30

22

2

12

26

18

Helium

Magnesium

Iron

Argon

Atomic Inventory

ElementElement SymbolSymbol AtomicAtomic

NumberNumber

Mass Mass NumberNumber

ProtonsProtons NeutronsNeutrons ElectronsElectrons

Zn

Br

Al

U

30

35

13

92

65

80

238

30

35

13

92

35

45

14

146

30

35

13

92

Zinc

Bromine

Aluminum

Uranium

27

Atomic Inventory

ElementElement SymbolSymbol AtomicAtomic

NumberNumber

Mass Mass NumberNumber

ProtonsProtons NeutronsNeutrons ElectronsElectrons

Na

Kr

Ca

Ag

11

36

20

47

23

84

40

108

11

36

20

47

12

48

20

61

11

36

20

47

Sodium

Krypton

Calcium

Silver