What is the smallest unit of an element that retains its properties?

• Electron

• Atom

• Molecule

• Proton

Which subatomic particles are found in the nucleus?

• Electrons and neutrons

• Protons and neutrons

• Electrons and protons

• Only protons

What determines the atomic number of an element?

• Number of protons

• Number of neutrons

• Number of electrons

• Number of atoms

Which particle has no charge?

• Proton

• Electron

• Neutron

• Positron

Which of the following best describes isotopes?

• Atoms with different numbers of protons

• Atoms with different numbers of neutrons

• Atoms with different numbers of electrons

• Atoms with the same number of neutrons

What is the mass number of an atom?

• Number of protons

• Number of neutrons

• Number of protons plus neutrons

• Number of electrons

Where are electrons located in an atom?

• In the nucleus

• In the electron cloud

• In the proton shell

• In the neutron shell

Which of the following elements is a diatomic molecule?

• Oxygen

• Carbon

• Helium

• Neon

Which group on the periodic table contains the most reactive metals?

• Group 1

• Group 2

• Group 17

• Group 18

What causes elements in the same group to have similar properties?

• Same number of protons

• Same number of neutrons

• Same number of electrons

• Same number of valence electrons