If oxygen in the air is O2 (since an oxygen atom has 6 electrons in the outer shell, it makes 2 double covalent bonds with another oxygen so that they’re both stable), why do oxygen molecules react with metals to form an oxide layer if O2 is stable? Its stable, so why react with anything?

Question

If oxygen in the air is O2 (since an oxygen atom has 6 electrons in the outer shell, it makes 2 double covalent bonds with another oxygen so that they’re both stable), why do oxygen molecules react with metals to form an oxide layer if O2 is stable? Its stable, so why react with anything?

In: Chemistry

Answer 1

As you probably know atomic oxygen has six outer electrons. When two oxygen atoms get together they share some elections so each atom “has the use of” eight (Google covalent bond). But copper atoms are willing to donate electrons “permanently” to oxygen atoms so both “own” complete outer shells which both find “more satisfying” (Google Ionic bond).

Of course “If you can’t measure it you don’t understand it” and the measurement of this “satisfaction” is the energy level referred to by other posters (lower energy = more satisfied).