The melting point of KCl is higher than that of AgCl though the crystal radii of `Ag^+` and `K^+` ions are almost though the crystal radii of `Ag^+` and `K^+` ions are almost the same.

Compare the radii of K^(+) and Cl^(-) ions (each contain the same number of electron).

A unit call of NaCl has four formula units. In NaCl crystal, radius ratio (r_(+)//r_(-)) is 0.69 and edge-length of the unit cell is twice the sum of the radii of Na^(+)andCl^(-) ions. If the radius of Na^(+) is 116 pm then find the density of NaCl crystal. Formula mass of NaCl = 58.5g*mol^(-1) .

Assertion (A) : Covalent crystals have higher melting point. Reason (R ) : Covalent bonds are stronger than ionic bonds.

Radii of K^(+)andO^(2-) ions are 1.51Å and 1..62Å, respectively. Predict the structure of K_(2)O .