Question

An atom that has a negative four charge will have which of the following?

Answer 1

Answer:

Anion with 4 more electrons than protons

Explanation:

In Atomic Theory, for a given element that is defined by the number of protons the only issue that can change is the number of valence electrons.

Therefore, element ions with a positive charge have lost electrons such that the number of protons is greater than the number of electrons. For element ions with a negative charge have gained electrons such that the number of protons is less than the number of electrons.

Examples:

Elements with positive charges => cations

Ca => Ca⁺² + 2e⁻ => Oxidation half-reaction shows electrons on right of arrow indicating 'loss' of electrons. This gives calcium (Ca⁺²) having 20p⁺ with 18e⁻.

Elements with negative charges => anions

O + 2e⁻ => O²⁻ => Reduction half-reaction shows electrons on left of arrow indicating a 'gain' of electrons. This gives oxygen (O²⁻) having 8p⁺ with 10e⁻.

Note on Periodic Trends of Ions

It should be noted that when looking at the periodic chart, the elements to the right of the metalloid elements are typically anions with greater numbers of electrons than protons on ionization. In the same context, the elements to the left of the metalloid elements are typically cations with greater numbers of protons than electrons on ionization. Metalloids are elements highlighted in yellow => B, Si, Ge, As, Sb, & Te.