Question

1. Complete the chart below on the composition of each atom below: Atomic Weight atomic number mass number number of protons number of number of electrons neutrons atom 27 Ra Ba 2

Answer 1

atom 227 Ra :

atomic weight = 227.035

atomic number = 88

Mass number = 227

number of protons = 88

number of electrons = 88

number of neutrons = 227 - 88 = 139

Ba+2 :

atomic weight = 137.3

atomic number = 56

mass number = 137

number of protons = 56

number of electrons = 54

number of neutrons = 81

3) selenium

Atomic weight = 78.96

Atomic number = 34

mass number = 78

Number of protons = 34

Number of electrons = 36

number of neutrons = 45

4) Iodine

Atomic weight = 127.9

Atomic number = 53

mass number = 127

number of protons = 53

number of electrons 53

number of neutrons = 74