Which of the following is always accompanied during a chemical change?

$\mathrm{I}$. Salt dissolved in water.
$\mathrm{II}$. Dissociation of salt in water.
$\mathrm{III}$. Decomposition of salt by electrolysis.

Codes

Which of the following represent a physical change?

$\mathrm{I}$. Cutting of carrot into pieces.
$\mathrm{II}$. Separation of iron and sulphur from their mixture.
$\mathrm{III}$. Separation of salt from sea-water.

Which of the following processes responsible for chemical change?

$\mathrm{I}$. Electrolysis
$\mathrm{II}$. Sublimation
$\mathrm{III}$. Corrosion
$\mathrm{IV}$. Decomposition

Code

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.