Valency

What is the valency of the following element?

Calcium in calcium oxide $\left(\mathrm{CaO}\right)$

What is the valency of the following element?

Potassium in potassium chloride $\left(\mathrm{KCl}\right)$

What is the valency of the following element?

Tin in stannic hydride $\left({\mathrm{SnH}}_4\right)$

What is the valency of the following element?

Calcium in calcium hydride $\left({\mathrm{CaH}}_2\right)$

What is the valency of the following element?

Lithium in lithium hydride $\left(\mathrm{LiH}\right)$

What is the valency of the following element?

Boron in boron hydride $\left({\mathrm{BH}}_3\right)$

What is the valency of the following element?

Sulphur in hydrogen sulphide $\left({\mathrm{H}}_2 \mathrm{S}\right)$

What is the valency of the following element?

Fluorine in hydrogen fluoride $\left(\mathrm{HF}\right)$

With a neat diagram, explain how aluminium hydride and lithium hydride are formed. What type of compounds are they?

Why are elements such as neon and argon unreactive?

What is variable valency? Explain with an example.

Identify the valency and number of valence electrons for silicon.

How will you find out the valency of an element from the periodic table? Look up the valency of potassium, barium and lead from the periodic table.

Give one word for the following.

The combining capacity of an element

If the number of valence electrons in an atom is $7$, its valency will be ________.

Elements such as neon and argon are unreactive.

Only metals exhibit variable valency.

Define the following term: Valency