What type of reaction occurs when an atom loses an electron?

When an atom loses an electron, it undergoes a process known as oxidation. This occurs because oxidation is defined as the loss of electrons or an increase in oxidation state by a chemical species. In the context of marine corrosion and electrochemistry, understanding oxidation is crucial, as it is often tied to the deterioration of metals in a marine environment.

Oxidation often involves metals reacting with elements such as oxygen, leading to corrosion products such as rust. The loss of electrons during oxidation also leads to the formation of positively charged ions, which can further participate in reactions.

The other types of reactions categorized in the question—reduction, combination, and decomposition—do not involve the direct loss of electrons as their defining characteristic. For instance, reduction refers to the gain of electrons by an atom or molecule, and combination reactions involve multiple reactants forming a single product, while decomposition reactions break down a compound into simpler substances. Understanding oxidation in this context helps clarify the processes that contribute to corrosion in marine settings.