LIFE SCIENCE

Detailed explanation-1: -The correct answer is: Electrons are shared to fill outer electron shells.

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 outer most (valence) electrons, atoms can fill up their outer electron shell and gain stability.

Detailed explanation-3: -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-4: -A covalent bond forms when two non-metal atoms share a pair of electrons . The electrons involved are in the outer shells of the atoms. An atom that shares one or more of its electrons will complete its outer shell.

Detailed explanation-5: -Covalent bonds involve the sharing of electron pairs between atoms. Electron pairs shared between atoms of equal or very similar electronegativity constitute a nonpolar covalent bond (e.g., H–H or C–H), while electrons shared between atoms of unequal electronegativity constitute a polar covalent bond (e.g., H–O).