91Ó°ÊÓ

We need to explain what will happen when the balloon blows up and when it is released.

Here, apply the principle of Avogadro's law.

A direct relationship between the volume $\left(V\right)$of the gas and the amount of the gas $\left(n\right)$. Increasing the amount of the gas it will be followed by an increase in the volume of the gas.

Avogadro's law's formula as:

$\frac{V_1}{n_1}=\frac{V_2}{n_2}$

$V_1$is initial volume,

$n_1$is the amount of the gas,

$V_2$is final volume and

$n_2$is the amount of the gas.

Now,

When blowing up the balloon, filling it with the air then increasing the amount of the air inside the balloon, according to Avogadro's law if followed by an increase in the volume of the balloon, therefore the balloon expands.

And, when releasing the balloon, air leaks our causing a decrease in the amount of the air inside the balloon, which according to Avogadro's law is followed by a decrease in the volume of the balloon.