What is the atomic number of helium?

• 1

• 2

• 3

• 4

Which of the following elements has an atomic number of 1?

• Helium

• Carbon

• Hydrogen

• Oxygen

What does the mass number of an atom represent?

• The number of protons only

• The number of neutrons only

• The total number of protons and neutrons

• The total number of electrons

Which isotope of hydrogen has one proton and one neutron?

• Protium

• Deuterium

• Tritium

• Helium

What is the significance of isotopes in radiometric dating?

• They determine the chemical properties of elements

• They help estimate the age of materials

• They define the element's position in the periodic table

• They influence the atomic number