State whether the following statement is true or false:
The decomposition reaction of silver bromide into silver and bromine by light is used in the manufacturing of cement.

Which one of the following is a chemical change? Give reason also.
$A$. Burning of wax
$B$. Melting of wax

Which among the following statement$(s)$ is(are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to
$(i)$ the formation of silver by decomposition of silver chloride
$(ii)$ sublimation of silver chloride
$(iii)$ decomposition of chlorine gas from silver chloride
$(iv)$ oxidation of silver chloride

Which among the following are physical or chemical changes?
$(a)$ Evaporation of petrol
$(b)$ Burning of Liquefied Petroleum Gas $(LPG)$
$(c)$ Heating of an iron rod to red hot
$(d)$ Curdling of milk
$(e)$ Sublimation of solid ammonium chloride

Give reasons for the following:
$(i)$ All decomposition reactions are endothermic reactions.
$(ii)$ Colour of copper sulphate solution changes when an iron nail is dipped in it.
$(iii)$ Respiration is an exothermic reaction.

Which of the following are combination reactions?
$(i)$ $2 KClO_{3} \xrightarrow{\text{Heat}} 2 KCl + 3O_{2}$
$(ii)$ $MgO + H_{2}O \longrightarrow Mg(OH)_{2}$
$(iii)$ $4 Al + 3O_{2} \longrightarrow 2 Al_{2}O_{3}$
$(iv)$ $Zn + FeSO_{4} \longrightarrow ZnSO_{4} + Fe$