The process of converting a solid directly into vapor without passing through the liquid state is called: MCQ with Answer and Explanation

Explanation:
Natural gas is primarily methane (CH₄), typically 70-90%, along with small amounts of ethane, propane, butane, and other hydrocarbons. It is a fossil fuel formed from the remains of ancient marine organisms. CNG (compressed natural gas) is methane stored at high pressure. LPG (liquefied petroleum gas) mainly contains propane and butane. Methane has the highest calorific value among the given options per unit mass.

Explanation:
Graham's Law of Diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of its density (or molar mass) at constant temperature and pressure (r ∝ 1/√d). Lighter gases diffuse faster than heavier ones, which explains why helium balloons deflate quickly.

Explanation:
Baking powder is a mixture of sodium bicarbonate (baking soda) and a mild edible acid, usually tartaric acid. When moistened and heated, they react to release CO₂, causing dough to rise. Baking soda alone requires an external acidic ingredient. The acid ensures complete reaction and avoids a bitter taste.