Calculate the mass of water and mass of glucose required to make $250 \, g$ of $40 \%$ solution of glucose.

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.

Sidak took $50\, mL$ of water in two beakers at room temperature and added sodium chloride to one beaker while sugar to the other,until no more solute could be dissolved. Then she heated the contents of the beakers and added more solutes in them.
$(a)$ Will the amount of salt and sugar that can be dissolved in water at a given temperature be the same?
$(b)$ What would you expect to happen if she cools the contents of the beakers? Justify your answer.

How is a pure substance different from a mixture?

What happens when a saturated solution is heated?

$(a)$ 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.