Which statement best explains why BaCl2 is an ionic compound? O A. BaCl, has a net charge of -2.
O B. The neutral atom Ba gains 2 electrons.
O C. BaCl, has a net charge of +2.
OD. The neutral atom Cl gains 1 electron.

D. The neutral atom Cl gains 1 electron.

Explanation:

Ionic bond:

It is the bond which is formed by the transfer of electron from one atom to the atom of another element.  

Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.

For example:

Barium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.89. There is large difference is present. That's why two valence electron from barium is transfer to the chlorine. Barium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations.  There are two valence electron lost by barium while chlorine required one electron to complete the octet thus two chlorine atoms are bonded with one barium atom. Each atom of chlorine carry -1 charge while one barium atom have +2 charge.

the correct answer is:

a population changes in response to a change in the environment.