Identify the symbol used for water according to $\text{Dalton's}$ atomic theory?

Identify the law for which the following statement is true.
"Equal volume of all gases at same temperature and pressure should contain equal number of molecules".

$5.06 \ g$ of pure cupric oxide $(CuO)$ on complete reduction gives $4.04 \ g$ of metallic copper. In another experiment,$1.3 \ g$ of metallic copper is dissolved in nitric acid and the resulting solution is carefully dried to yield $1.63 \ g$ of $CuO$. Which law of chemical combination is illustrated by these results?

Explain Dalton's atomic theory.

Zinc sulphate contains $22.65\%$ of zinc and $43.9\%$ of water of crystallization. If the law of constant proportions is true,then the weight of zinc required to produce $20\, g$ of the crystals will be ............. $g$.

Which of the following pairs of substances illustrates the Law of Multiple Proportions?