"Mass can neither be created nor destroyed" is the statement of

The following data are obtained when dinitrogen and dioxygen react together to form different compounds:

Mass of dinitrogen	Mass of dioxygen
$14 \ g$	$16 \ g$
$14 \ g$	$32 \ g$
$28 \ g$	$32 \ g$
$28 \ g$	$80 \ g$

Which law of chemical combination is obeyed by the above experimental data?

"$A$ given compound always contains the same proportion of elements" is a statement of $-$

Ammonia contains $82.35\%$ nitrogen and $17.65\%$ hydrogen. Water contains $88.90\%$ oxygen and $11.10\%$ hydrogen. Nitrogen dioxide contains $63.15\%$ oxygen and $36.85\%$ nitrogen. Which law can be illustrated by the given data?

Explain Avogadro's Law with the help of a figure.

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