Describe the activity to construct a simple electroscope.

(N/A) $1$. Take a thin aluminium curtain rod with ball ends, typically used for hanging curtains.
$2$. Cut a piece of the rod approximately $20 \,cm$ long, ensuring one end has the ball and the other end is flattened.
$3$. Take a large bottle that can accommodate the rod and a cork that fits securely into the bottle's opening.
$4$. Insert the rod through the cork such that about $5 \,cm$ of the ball end projects above the cork.
$5$. Fold a small, thin strip of aluminium foil (about $6 \,cm$ in length) in the middle and attach it to the flattened end of the rod using cellulose tape.
$6$. Place a paper scale inside the bottle beforehand to measure the separation of the aluminium leaves.
$7$. The separation between the leaves provides a rough measure of the amount of charge present on the electroscope.