Ionic or Electrovalent Bond

When ${\mathrm{X}}_{\mathrm{A}}>>{\mathrm{X}}_{\mathrm{B}}, \mathrm{A}-\mathrm{B}$ bond is :

The crystalline structure of $\mathrm{NaCl}$ is 

The metal ion with total number of electrons same as ${\mathrm{S}}^{2-}$ is

Which of the following is a monoatomic ion?

Draw the crystal structure of sodium chloride.

The structure of sodium chloride is formed by repeating the _____ cubic unit cell.

${\mathrm{AlCl}}_3$ is an electron deficient compound but ${\mathrm{AlF}}_3$ is not. This is because

Assertion $\left(\mathrm{A}\right):$ Covalent character follows: $\mathrm{NaCl}<{\mathrm{MgCl}}_2<{\mathrm{BeCl}}_2<\mathrm{LiCl}$
Reason $\left(\mathrm{R}\right):$ According to Fajan's rules, covalent character of ionic compounds increases with decrease in size of cation.

 Which of the following statement is incorrect?

Arrange $\mathrm{N}, \mathrm{S}, \mathrm{O} \& \mathrm{F}$ in order of decreasing electron gain enthalpy

 Which among the following compound shows the highest lattice energy? 

Assertion $\left(\mathrm{A}\right):$ The first ionization energy of $\mathrm{Be}$ is greater than that of $\mathrm{B}.$

Reason $\left(\mathrm{R}\right):$ $2\mathrm{p}$ orbital has lower energy than $2\mathrm{s}$ orbital.

Which of the following compounds is polar ?

Name the bond formed by calcium and oxide ions.

An element with the atomic number $19$ will most likely combine chemically with the element whose atomic number is

$\mathrm{K}\mathrm{ }\left[\mathrm{B}\mathrm{r}\mathrm{I}\mathrm{C}\mathrm{l}\right]\mathrm{ }\stackrel{\mathrm{\Delta }}{\to }\mathrm{ }\left(\mathrm{X}\right)\mathrm{ }+\mathrm{ }\left(\mathrm{Y}\right)$

Which of the following compounds contain(s) no covalent bond(s)?

$\mathrm{KCl},\mathrm{ }{\mathrm{PH}}_3,\mathrm{ }{\mathrm{O}}_2,\mathrm{ }{\mathrm{B}}_2{\mathrm{H}}_6,\mathrm{ }{\mathrm{H}}_2{\mathrm{SO}}_4$