Give some examples of the Tyndall effect observed in your surroundings.

Give an example for each of the following:
$(a)$ Solid-liquid homogeneous mixture
$(b)$ Gas-gas homogeneous mixture
$(c)$ Solid-solid homogeneous mixture
$(d)$ Solid-liquid heterogeneous mixture
$(e)$ Liquid-liquid heterogeneous mixture

Two substances,$A$ and $B$,were made to react to form a third substance,$A_2B$,according to the following reaction: $2A + B \to A_2B$. Which of the following statements concerning this reaction are incorrect?
$(i)$ The product $A_2B$ shows the properties of substances $A$ and $B$.
$(ii)$ The product will always have a fixed composition.
$(iii)$ The product so formed cannot be classified as a compound.
$(iv)$ The product so formed is an element.

State whether the following statement is true or false:
The properties that can be observed and specified are called physical properties.

How can we separate a mixture of two immiscible liquids?

$(a)$ What separation technique will you apply for the separation of the following?
$(i)$ Ammonium chloride from sodium chloride.
$(ii)$ Different pigments from the extract of flower petals.
$(b)$ What is crystallisation? List two ways in which the crystallisation technique is better than the simple evaporation technique.