When calcium carbide is reacted with heavy water, which of the following product(s) will be formed

I. $\mathrm{CD}_4$

II. $\mathrm{C}_2 \mathrm{D}_2$

III. $\mathrm{Ca}(\mathrm{OD})_2$

IV. $\mathrm{Ca}_2 \cdot \mathrm{D}_2 \mathrm{O}$

Which alkali metal emits blue colour light in flame test?

$$ \text { Match the following : } $$

Glass reacts with HF to produce