AP BIOLOGY

Detailed explanation-1: -A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. These electrons are simultaneously attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions.

Detailed explanation-2: -Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outermost (valence) electrons, atoms can fill up their outer electron shell and gain stability.

Detailed explanation-3: -Answer (B) Double covalent bond. A Double covalent bond is formed when two pairs of electrons are shared between the atoms rather than just one pair.