What is true of a covalent bond?
it is the electrostatic attraction between oppositely charged particles

it is the sharing of electrons by overlapping orbitals

it involves the exchange of electrons from one atom to another

it involves the sharing of neutrons between two nuclei

it is the sharing of electrons by overlapping orbitals

Explanation:

Covalent bonds occurs when the reacting elements share their valence electrons in order to attain the duplet or octet configuration of the noble gas.

This reaction is A. Spontaneous at high temperatures, and non-spontaneous at low temperatures.

Explanation:

Both the enthalpy change and the entropy change due to this reaction are positive. A chemical reaction will be spontaneous only if the change in its Gibbs Free Energy is negative. is the absolute temperature in degrees Kelvins.

Assume that both and doesn't change much as increases. The value of will initially be close to when is small. The sign of will depends on that of . However, is positive, so at low temperatures will be positive and the reaction will be non-spontaneous.

However, as increases, the role of entropy change becomes more significant. The sign of will eventually be the opposite of . The value of will eventually drop below zero after the value of rises above . The reaction will eventually become spontaneous.