when metals react do they gain or lose electrons?

Metals normally lose electrons when they react, not gain them.

Core idea

• Metal atoms tend to lose their outer (valence) electrons and become positively charged ions called cations.

• The species they react with (often non‑metals or metal ions in solution) gain those electrons and become reduced.

Why metals lose electrons

• Metals usually have only 1–3 electrons in their outer shell, so it is easier (takes less energy) to lose these few electrons than to gain many more to fill the shell.

• After losing electrons, the metal ion ends up with a stable, noble‑gas‑like electron configuration, which is energetically favorable.

In terms of oxidation and reduction

• Oxidation = loss of electrons (often happens to metals in reactions such as rusting or burning).

• Reduction = gain of electrons (often happens to non‑metals or metal ions receiving electrons from a metal atom).

Simple example

• When sodium reacts with chlorine, sodium loses one electron to form Na⁺, and chlorine gains that electron to form Cl⁻; the sodium has been oxidized, and the chlorine reduced.

TL;DR: When metals react, they usually lose electrons and become positive ions; the other reactant gains those electrons.