Dolomite is an ore of which metal?

What is the percentage of $H_{2}SO_{4}$ in concentrated $H_{2}SO_{4}$ (in $\%$)?

Write the balanced chemical equation for each of the following cases:
$(a)$ Magnesium is treated with very dilute $HNO_3$.
$(b)$ Aluminium powder is added to $Fe_2O_3$.
$(c)$ Zinc sulphide is roasted.

Provide one exception for each of the following general statements:
$(i)$ Metals are lustrous.
$(ii)$ Metals are solids at room temperature.
$(iii)$ Metals have high melting points.
$(iv)$ Non-metals are non-lustrous.
$(v)$ Non-metals are insulators or non-conductors of electricity.

Make correct pairs from the below-mentioned $X$ and $Y$:

$X$	$Y$
$1.$ Dehydrating agent	$p.$ Sulphur dioxide gas
$2.$ In preparation of firecrackers	$q.$ Concentrated sulphuric acid
$3.$ Weak bleaching agent	$r.$ Dihydrogen gas
$4.$ Lightest gas	$s.$ Sulphur

$(i)$ Name a metal which does not stick to glass.
$(ii)$ Name the metal which is commonly used in thermite welding.
$(iii)$ What is the nature of zinc oxide?