Write true or false for the following statement:
Due to corrosion, iron gets a brown coating, copper gets a green coating, and silver gets a black coating.

Which of the following is(are) an endothermic process(es)?
$(i)$ Dilution of sulphuric acid
$(ii)$ Sublimation of dry ice
$(iii)$ Condensation of water vapours
$(iv)$ Evaporation of water

$A$ metal $P$,when exposed to moist air for a longer period of time,loses its shiny brown surface and gains a green coat. Why has this happened? Identify the metal. Write the name and chemical formula of this green-coloured compound. List two ways to prevent this process.

Which of the following is(are) an endothermic process(es)?
$(i)$ Dilution of sulphuric acid
$(ii)$ Sublimation of dry ice
$(iii)$ Condensation of water vapours
$(iv)$ Evaporation of water

An aluminium can was used to store ferrous sulphate solution. It is observed that in a few days,holes appeared in the can. Explain the observation and write the chemical equation to support your answer.

$A$ magnesium ribbon is burnt in oxygen to give a white compound $X$ accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen,it continues to burn and forms a compound $Y.$
$(a)$ Write the chemical formulae of $X$ and $Y.$
$(b)$ Write a balanced chemical equation,when $X$ is dissolved in water.