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

Explanation:
Combination: two or more reactants combine to one product. Mg and O₂ combine to form MgO. A is decomposition; B is displacement; D is double displacement.

Explanation:
Electrolysis of water produces pure hydrogen and oxygen: 2H₂O → 2H₂ + O₂. Hydrogen is used in fuel cells to generate electricity. It can also be produced by steam reforming of natural gas, but electrolysis yields clean hydrogen if powered by renewable energy. Combustion of methane produces energy, not hydrogen. Neutralization gives salt and water.

Explanation:
Metalloids (B, Si, Ge, As, Sb, Te) are located along the staircase line on the right side of the p-block, dividing metals from non-metals. They exhibit intermediate properties: semiconductors, brittle, can form alloys. They are in groups 13-17. The s-block contains reactive metals. Group 18 contains noble gases. f-block contains lanthanides and actinides.