Name the process of gain of hydrogen.

Oxidation is the loss of electron and reduction is the gain of electron. On the basis of these concepts select the species (i) oxidized, and (ii) reduced in the following reactions.

$\mathrm{Zn}\left(\mathrm{s}\right) + {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)\to {\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)+ \mathrm{Cu}\left(\mathrm{s}\right)$

Oxidation is the loss of electron and reduction is the gain of electron. On the basis of these concepts select the species (i) oxidized, and (ii) reduced in the following reactions.

$\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{Cl}}_2\left(\mathrm{g}\right) \to {\mathrm{MgCl}}_2\left(\mathrm{s}\right)$

Oxidation is the loss of electron and reduction is the gain of electron. On the basis of these concepts select the species (i) oxidized, and (ii) reduced in the following reactions.

$\mathrm{Fe}\left(\mathrm{s}\right) + 2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{FeCl}}_2\left(\mathrm{aq}\right) + {\mathrm{H}}_2\left(\mathrm{g}\right)$

Select the physical and chemical changes from the following:

Burning of magnesium

State whether the given change is physical or chemical.

Boiling of water