How many electrons are present in one molecule of CH₄?

Identify the longest carbon chain and mention the number of carbons present in it.

Element X belongs to period 2 and group 1 of the periodic table. State the formula of the chloride of the element X.

Anurag added dilute H₂SO₄ to a given sample X and heated the mixture. He observed that a gas was liberated which had a foul smell of rotten eggs and it turned moist lead acetate paper silvery black. Name the gas evolved in the above case.