In an oxygen molecule, two atoms are united by A. One bond B. Two bonds C. Three bonds D. Four bonds

The correct answer is: B. Two bonds.

An oxygen molecule is made

up of two oxygen atoms that are joined together by a double covalent bond. A covalent bond is a chemical bond that involves the sharing of electrons between atoms. In a double covalent bond, two pairs of electrons are shared between the atoms. This type of bond is stronger than a single covalent bond, which is why oxygen molecules are very stable.

Option A is incorrect because an oxygen molecule does not have one bond. Option C is incorrect because an oxygen molecule does not have three bonds. Option D is incorrect because an oxygen molecule does not have four bonds.