Give the structure of ammonium ion and hydroxyl ion.

Element $\mathrm{X}$ is a metal with valency $2$, element $\mathrm{Y}$ is a non-metal with a valency $3$.

Write equations to show how $\mathrm{X}$ and $\mathrm{Y}$ form ions.

Element $\mathrm{X}$ is a metal with valency $2$, element $\mathrm{Y}$ is a non-metal with a valency $3$.

If $\mathrm{Y}$ is a diatomic gas, write the equation for the direct combination of $\mathrm{X}$ and $\mathrm{Y}$ to form a compound.

Element $\mathrm{X}$ is a metal with valency $2$, element $\mathrm{Y}$ is a non-metal with a valency $3$.

If the compound formed between $\mathrm{X}$ and $\mathrm{Y}$ is melted and an electric current passed through the molten compound element $\mathrm{X}$ will be obtained at the ______ and $\mathrm{Y}$ at the _____ of the electrolyte.  

Compound $\mathrm{X}$ consists of molecules.

Choose the correct answer from the choices given below:

The bonding in $\mathrm{X}$ will be:

Compound $\mathrm{X}$ consists of molecules.

Choose the correct answer from the choices given below:

$\mathrm{X}$ is likely to have:

Compound $\mathrm{X}$ consists of molecules.

Choose the correct answer from the choices given below:

In the liquid state $\mathrm{X}$ will be: