$A$ balloon filled with helium ($32^{\circ} C$ and $1.7 \; atm$) bursts. Immediately afterwards,the expansion of helium can be considered as:

$Assertion :$ Thermodynamic processes in nature are irreversible.
$Reason :$ Dissipative effects cannot be eliminated.

For the free expansion of a gas,which of the following is true?

Is the rusting of iron a reversible process? Why?

Given below are two statements. One is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A) :$ In an insulated container,a gas is adiabatically shrunk to half of its initial volume. The temperature of the gas decreases.
Reason $(R) :$ Free expansion of an ideal gas is an irreversible and an adiabatic process.
In the light of the above statement,choose the correct answer from the options given below :

For the free expansion of a gas,which of the following is true?