Question

16
s
sulfur
32.06
atomic # =
atomic mass =
mass number =

of protons =

of neutrons =

of electrons =

12
mg
magnesium
24.305
atomic # =
atomic mass =
mass number =

of protons =

of neutrons =

of electrons =

79
au
gold
196.967
atomic # =
atomic mass =
mass number =

of protons =

of neutrons =

of electrons =

Explanation:

Step1: Recall atomic number definition

Atomic number is the number at the top of the element box.

Step2: Recall atomic mass

Atomic mass is the number at the bottom of the element box.

Step3: Recall mass - number concept

Mass number is the whole - number closest to the atomic mass.

Step4: Recall proton - atomic number relation

Number of protons equals atomic number.

Step5: Calculate neutrons

Number of neutrons = Mass number - Number of protons.

Step6: Recall electron - proton relation

In a neutral atom, number of electrons equals number of protons.

For Sulfur (S):

Atomic # = 16
Atomic Mass = 32.06
Mass Number = 32

of Protons = 16

of Neutrons = 32 - 16=16

of Electrons = 16

For Magnesium (Mg):

Atomic # = 12
Atomic Mass = 24.305
Mass Number = 24

of Protons = 12

of Neutrons = 24 - 12 = 12

of Electrons = 12

For Gold (Au):

Atomic # = 79
Atomic Mass = 196.967
Mass Number = 197

of Protons = 79

of Neutrons = 197 - 79 = 118

of Electrons = 79

Answer:

Sulfur:
Atomic # = 16
Atomic Mass = 32.06
Mass Number = 32

of Protons = 16

of Neutrons = 16

of Electrons = 16

Magnesium:
Atomic # = 12
Atomic Mass = 24.305
Mass Number = 24

of Protons = 12

of Neutrons = 12

of Electrons = 12

Gold:
Atomic # = 79
Atomic Mass = 196.967
Mass Number = 197

of Protons = 79

of Neutrons = 118

of Electrons = 79