Write the equation for the reaction aluminium with air?

An element X (atomic number 20) reacts with another element Y (atomic number 17) to form a compound X. Which of the following statement are true regarding compound Z. Which of the following statement are true regarding this compound?

I. Molecular formula of of X is ${\mathrm{XY}}_2$.

II. X and Y are joined by sharing of electrons.

III. Z imparts characteristic flame colour.

IV. It is soluble in water.

Statement (A): Iron does not burn on heating.

Statement (B): Iron filings burn vigorously when sprinkled in the flame of the burner.

Give balanced chemical equation for following reaction-

$\mathrm{Na} + {\mathrm{O}}_2 \stackrel{ }{\to } {\mathrm{Na}}_2\mathrm{O}$

Attempt the following:

The metal sodium is kept immersed in Kerosene oil in the school laboratory. Why it is not kept the open?

The equation of the reaction when aluminium is heated in air is given below.

$\mathrm{x} \mathrm{Al} + {\mathrm{yO}}_2 \to {\mathrm{zAl}}_2{\mathrm{O}}_3$

The value of ‘z’ when the reaction is balanced is:

Why is sodium kept immersed in kerosene oil? 

Give reason:

Metals like sodium and potassium are stored under oil.

Write the chemical equation for the following events.

Aluminium came in contact with air.

You could have noted that when copper powder is heated in a china dish the surface of copper becomes black coloured.

What is the black substance?

The electronic configuration of metal ‘A’ is 2,8,1 and that of metal ‘B’ is 2,8,2. Which of the two metals is more reactive? Write their reaction with dilute hydrochloric acid.