Table of contents

2. Atoms & Elements

Ions

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Multiple Choice

When an atom of magnesium (Mg) loses two electrons, which ion is formed?

Mg^{2+}

Mg^{-1}

Mg^{+}

Mg^{-2}

Verified step by step guidance

Understand that when an atom loses electrons, it becomes a positively charged ion called a cation.

Recall that magnesium (Mg) has an atomic number of 12, meaning it has 12 protons and normally 12 electrons in its neutral state.

When magnesium loses two electrons, the number of electrons decreases from 12 to 10, while the number of protons remains 12.

The loss of two negatively charged electrons results in a net positive charge of +2 on the ion.

Therefore, the ion formed is represented as $Mg^{2+}$, indicating a magnesium ion with a +2 charge.

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