Question

name the gas in air which tarnishes silver article slowly​

Answer 1

Answer:

sulphur dioxide

which makes AgS

Answer 2

Answer:

Mg and Ca belong to group 2, but

periods 2 and 3, respectively. During the reaction with air, the metallic Mg and Ca lose their valence electrons. The tendency ro lose valence electron is the metallic character, which increases down the group. Thus, calcium has higher metallic character, greater tendency to lose valence electron and lower ionisation enthalpy than magnesium. Therefore, Mg reacts slowly with air, forming a thin film of oxide, resulting into tarnishing, whereas Ca reacts readily at room temperature with oxygen and nitrogen in the air.