Question

Consider two stable isotopes, helium-3 and helium-4. How many neutrons and protons are there in each isotope? What are the mass numbers?

a) Helium-3: 1 proton, 2 neutrons, Mass number: 3
Helium-4: 2 protons, 2 neutrons, Mass number: 4
b) Helium-3: 2 protons, 1 neutron, Mass number: 3
Helium-4: 2 protons, 2 neutrons, Mass number: 4
c) Helium-3: 1 proton, 2 neutrons, Mass number: 4
Helium-4: 2 protons, 2 neutrons, Mass number: 3
d) Helium-3: 2 protons, 1 neutron, Mass number: 4
Helium-4: 2 protons, 2 neutrons, Mass number: 3

Answer 1

Helium-3 has 1 proton and 2 neutrons with a mass number of 3, while helium-4 has 2 protons and 2 neutrons with a mass number of 4.

Step-by-step explanation:

Helium-3, also known as 3He, has 1 proton and 2 neutrons, with a mass number of 3. Helium-4, also known as 4He, has 2 protons and 2 neutrons, with a mass number of 4. The number of protons determines the identity of an element, whereas the number of neutrons can vary, resulting in different isotopes with different mass numbers.