Question

In a crystal, cations and anions are held together by:
A. Electrons
B. Electrostatic forces
C. Nuclear forces
D. Covalent bonds

Answer 1

Hint: Crystals are classified according to the nature of binding forces holding the constituent particles together. Cations and anions are constituents of ionic solids. The given question can be answered if we know the nature of bonding forces in ionic solids.

Complete step-by-step answer:
Ionic crystals are those crystals that have ionic bonds, resulting between two atoms by the total transfer of valence electrons from one atom to another, so that each atom attains a stable electronic configuration. The resulting positive and negative ions attract each other by Coulomb’s law force which dominates the Columbian repulsive forces between positive and negative ions. After the transfer of electrons in ionic solids, the ions attain electronic configuration as inert gas atoms. $NaCl$, $KCl$, $KBr$, $MgO$ and $KOH$ are some examples of ionic crystals.
Thus, we can conclude, in ionic solids or crystals, there is a regular arrangement of positively charged ions, called cations, and negatively charged ions, called anions, throughout the solid. The cations and anions are held together by strong electrostatic forces.

Hence, option B is the correct answer.

Note: Due to the presence of strong electrostatic forces, ionic solids have high melting and boiling points. Also, ionic solids have low volatility, high density and high stability. Ionic crystals are hard, brittle and soluble in polar solvents.
Molecular or covalent crystals having small molecules as constituents, have covalent bonds between their molecules.
Metallic solids have positive ions as constituents, which are held together by free moving electrons.
No crystal, has its constituents held together by nuclear forces.