$(a)$ Explain with the help of an activity which shows that particles of matter are very small.
$(b)$ Define matter. Name the states of matter in which the forces between the constituent particles are
$(i)$ strongest
$(ii)$ weakest
$(c)$ When sugar and common salt are kept in different jars,they take the shape of the jars. Are they solid? Justify your answer.

(N/A) Activity:
$(i)$ Take $2-3$ crystals of copper sulphate and dissolve them in $100\, mL$ of water.
$(ii)$ Take out approximately $10\, mL$ of this solution and put it into $90\, mL$ of clear water.
$(iii)$ Take out $10\, mL$ of this solution and put it into another $90\, mL$ of clear water.
$(iv)$ Keep repeating this process of dilution.
Observation:
$A$ crystal of copper sulphate contains millions of tiny particles which keep on dividing into smaller and smaller numbers with each dilution. This shows that particles of matter are very small.
$(b)$ Matter is anything that has mass and occupies space.
$(i)$ Solid: The forces between constituent particles are strongest in solids.
$(ii)$ Gas: The forces between constituent particles are weakest in gases.
$(c)$ Yes,sugar and common salt are solids. Although they take the shape of the container they are kept in,the shape of each individual crystal remains fixed. Therefore,they are considered solids.