The forces that hold different atoms or ions together are
a. electric currents.
c. physical bonds.
b. chemical bonds.
d. nuclear forces.

The force that hold different atoms or ions together is chemical bonds.

Explanation:

Chemical bonds are defined as the bonds which are formed by the combination of atoms or ions.

Ionic bonds are defined as the bonds which are formed by the complete transfer of electrons from cation (positively charged ions) to anion (negatively charged ions). For Example: NaCl, etc...

Covalent bond is defined as the bond which is formed by the sharing of electrons between the atoms. For Example: HCl, etc..

Nuclear forces are defined as the forces which is present between the neutrons and protons present in the nucleus. It is the binding force.

An electric current is defined as the rate of flow of electric charge at a point.

Hence, the force that hold different atoms or ions together is chemical bonds.

the product of the pressure and volume is also constant