Select the correct answer. When an atom in a reactant loses electrons, what happens to its oxidation number? A. Its oxidation nu
mber decreases. B. Its oxidation number doubles. C. Its oxidation number increases. D. Its oxidation number increases by one. E. Its oxidation number stays the same.
<em><u>Oxidation is defined as the loss of electrons by an atom while reduction is the gain of electrons by an atom</u></em>.
Atoms of elements have an oxidation number of Zero in their elemental state.
When an atom looses electrons it undergoes oxidation and its oxidation number increases.
For example, <em><u>an atom of sodium (Na) at its elemental state has an oxidation number of 0. When the sodium atom looses an electrons it becomes a cation, Na+, with an oxidation number of +1 , the loss of electron shows an increase in oxidation number from 0 to +1.</u></em>
When oxidation occurs, an element loses electrons and its oxidation number increases (becomes more positive). When reduction occurs, an element gains electrons and its oxidation number decreases or is reduced (becomes more negative).
