PRACTICE
1 Chlorine has two stable isotopes, chlorine-35 and chlorine-37. The
atomic number of chlorine is 17. Calculate the numbers of protons,
electrons, and neutrons each isotope has.

1. For isotope A (chlorine 35)

Proton = 17

Electron = 17

Neutron = 18

2. For isotope B (chlorine 37)

Proton = 17

Electron = 17

Neutron = 20

Explanation:

Let isotope A be chlorine-35

Let isotope B be chlorine-37

1. For isotope A (chlorine-35)

Data obtained from the question include:

Atomic number = 17

Mass number = 35

Proton number = atomi number

Proton number = 17

Since the isotope is neutral,

Electron number = proton number

Electron number = 17

Mass number = Neutron + proton

Neutron = Mass number - proton

Neutron = 35 - 17

Neutron number = 18

2. For isotope B (chlorine-37)

Data obtained from the question include:

Atomic number = 17

Mass number = 37

Proton number = atomi number

Proton number = 17

Since the isotope is neutral,

Electron number = proton number

Electron number = 17

Mass number = Neutron + proton

Neutron = Mass number - proton

Neutron = 37 - 17

Neutron number = 20

the answers would be

the first one and the second one