Atomic Structure

What are the three subatomic particles found in an atom?

• Protons, neutrons, electrons

• Protons, electrons, photons

• Protons, neutrons, positrons

• Protons, electrons, neutrinos

Answer explanation

The three subatomic particles that make up an atom are protons, neutrons, and electrons. Protons and neutrons are found in the nucleus, or centre, of the atom, while electrons orbit around the nucleus.

Which subatomic particle has a positive charge?

• Proton

• Neutron

• Electron

• Photon

Which subatomic particle has no charge?

• Proton

• Neutron

• Electron

• Photon

Which subatomic particle has a negative charge?

• Proton

• Neutron

• Electron

• Photon

What is the relative mass of a proton?

• 1

• 0

• 1/1836

• Unknown

What is the relative mass of a neutron?

• 1

• 0

• 1/1836

• Unknown

What is the relative mass of an electron?

• 1

• 0

• 1/1836

• Unknown

What is the atomic number of an atom?

• The number of protons

• The number of neutrons

• The number of electrons

• The number of shells

What is the mass number of an atom?

• The number of protons and neutrons

• The number of neutrons

• The number of electrons

• The number of protons

What is an isotope?

• An atom with a different number of protons

• An atom with a different number of neutrons

• An atom with a different number of electrons

• An atom with a different number of shells

Answer explanation

An isotope refers to an atom with a different number of neutrons. While all atoms of a certain element have the same number of protons, the neutron count can vary, creating different isotopes of the same element. The other options are incorrect as they describe ions (different number of electrons) and shells are related to electron configuration.