What is the percentage of $H_{2}SO_{4}$ in dilute sulfuric acid (in $\%$)?

Which alloy is used for making aircraft parts?

Which element forms the basis of components like vitamins,proteins,and carbohydrates?

Write chemical equations for the reactions taking place when:
$(i)$ Iron reacts with steam.
$(ii)$ Magnesium $(Mg)$ reacts with dilute $HCl$.
$(iii)$ Copper is heated in air.

When finely powdered ore is placed on a rotating grooved table and rotated rapidly,the lighter impurities are removed. What is this method of concentration called?

In the electrolytic refining of metals, the insoluble impurities present in the impure metal settle down at the bottom of the container below the anode. What is this called?