Which among the following is a chemical change?

Which of the following represent both physical and chemical change?

$\mathrm{I}$. Burning of candle.
$\mathrm{II}$. Burning of methane.
$\mathrm{III}$. Decomposition of salt.

Which of the following processes is related to chemical change?

$\mathrm{I}$. Movement of free electrons in copper wire.
$\mathrm{II}$. Electric current passes through copper wire.
$\mathrm{III}$. Electric current passes through $\mathrm{NaCl}$ aqueous solution.

Which of the following represent a chemical change?

$\mathrm{I}$. Magnetisation of iron.
$\mathrm{II}$. Condensation to liquid.
$\mathrm{III}$. Burning of fuel.
$\mathrm{IV}$. Rusting of iron.