Arrange the following elements from greatest to least tendency to accept an electron. Rank from greatest to least tendency to accept an electron. To rank items as equivalent, overlap them.

Mg, Si, Na, S, Cl

The order of the elements from greatest to least tendency to accept an electron is Cl, S, Si, Na, Mg.

The tendency to accept an electron can be measured through the electron affinity (EA). The electron affinity is defined as the amount of energy released when an electron is attached to a neutral atom or molecule in the gaseous state to form a negative ion.

X(g) + e⁻ → X⁻(g) + energy

Generally, nonmetals have greater EA than metals, since nonmetals tend to gain electrons to completer their octets, while metals tend to lose electrons to complete theirs. We can verify this trend by looking at the values of EA.

Cl (349 kJ/mol) > S (200 kJ/mol) > Si (134 kJ/mol) > Na (53 kJ/mol) > Mg (-40 kJ/mol)

The order of the elements from greatest to least tendency to accept an electron is Cl, S, Si, Na, Mg.

You can learn more about electron affinity here: