An element $\mathrm{X}$ forms two oxides $\mathrm{XO}$ and ${\mathrm{XO}}_2$. The oxide $\mathrm{XO}$ is neutral but ${\mathrm{XO}}_2$ is acidic in nature. The element $\mathrm{X}$is most likely to be

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.

An element $\mathrm{X}$ forms two oxides $\mathrm{XO}$ and ${\mathrm{XO}}_2$. The oxide $\mathrm{XO}$ is neutral but ${\mathrm{XO}}_2$ is acidic in nature.The element $\mathrm{X}$ is most likely to be 

Four elements W, X, Y, and Z have atomic numbers 12,18, 4, and 16:

Which of the above will form an acidic oxide?

What is the product when sulphur reacts with oxygen?

Which of the following products are obtained when hydrogen reacts with chlorine atom?

Observe the given figure carefully.

The residue left behind in the crucible, substance $Y$ and the substance which can replace $Y$ in the above process are respectively

Nitric acid oxidises sulphur to: