Ionic diagrams for binary ionic substances | Starter Quiz | Oak National Academy

Magnesium is in Group 2 of the periodic table. Which of the following statements about magnesium ions are correct?

• Magnesium atoms have two electrons in their outer shell.

• Magnesium ions are more stable than magnesium atoms.

• Magnesium ions have two electrons in their outer shell.

• Magnesium atoms can be represented by the symbol Mg²⁺.

Answer explanation

Magnesium atoms lose two electrons to form more stable magnesium ions. Magnesium ions are represented by the symbol Mg²⁺.

Oxygen is a non-metal. What name is given to the type of ions that oxygen forms?

Answer explanation

Anions are negative ions formed when non-metal atoms, like oxygen, gain electrons.

Which of the following symbols represents a sodium ion?

• Na⁺

• Na²⁺

• Na⁻

• Na²⁻

Answer explanation

Sodium atoms lose one electron to form a more stable sodium ion.

True or false? Bromine atoms form stable Br⁻ ions.

• true

• false

Answer explanation

Bromine atoms have seven electrons in their outer shell. They gain one electron to form bromine ions.

Neon is found in Group 0 of the periodic table. Why is neon unreactive?

• Neon atoms do not need to lose or gain electrons to fill their outer shell.

• Neon atoms are stable.

• Neon atoms contain 0 electrons in their outer shell.

• Neon atoms have a full outer shell of electrons.

Answer explanation

Atoms gain or lose electrons to become more stable. Group 0 elements have a full outer shell of electrons, this makes them stable and unreactive.

An element has atoms containing 20 electrons. Which of the following statements about the element are true?

• The atoms of the element have 2 electrons in the outer shell.

• The element forms ions with a charge of 2+.

• The atoms of the element have 3 shells of electrons.

• The element forms ions with a charge of 2-.

• The atom is a metal.

Answer explanation

The electron configuration for the element is 2,8,8,2. This means it loses two electrons to form a stable ion with a 2+ charge.