Which of the following statements are true for pure substances?
$(i)$ Pure substances contain only one kind of particles.
$(ii)$ Pure substances may be compounds or mixtures.
$(iii)$ Pure substances have the same composition throughout.
$(iv)$ Pure substances can be exemplified by all elements other than nickel.

State the separation technique you would apply for the separation of the following:
$(a)$ Sodium chloride from its solution in water
$(b)$ Tea leaves from tea
$(c)$ Iron pins from sand
$(d)$ Different pigments from an extract of leaves
$(e)$ Butter from curd
$(f)$ Fine mud particles suspended in water.

Write one point of difference between concentration and solubility.

Two chemical species $X$ and $Y$ combine together to form a product $P$ which contains both $X$ and $Y$.
$X + Y \to P$
$X$ and $Y$ cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species $X$,$Y$ and $P$ are correct?
$(i)$ $P$ is a compound
$(ii)$ $X$ and $Y$ are compounds
$(iii)$ $X$ and $Y$ are elements
$(iv)$ $P$ has a fixed composition

$(a)$ 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.

$(a)$ Compare metals and non-metals based on their physical properties. (any four points)
$(b)$ What are metalloids? Give two examples.
$(c)$ Identify metals from the following: Boron,sodium,mercury,carbon.