The depletion of the ozone layer is mainly caused by: MCQ with Answer and Explanation

Explanation:
Combined gas law combines Boyle's, Charles', and Gay-Lussac's laws for a fixed mass of gas. It relates P, V, T when all change. PV=nRT is ideal gas equation for n moles.

Explanation:
Portland cement is made by heating a mixture of limestone (CaCO₃) and clay (SiO₂, Al₂O₃, Fe₂O₃) in a kiln. The resulting clinker is ground with gypsum. Soda ash and sand are for glass.

Explanation:
Ionic compounds are soluble in polar solvents like water. In the solid state, ions are fixed in a lattice and cannot move, so they don't conduct. However, in molten or aqueous states, the ions become free to move, allowing them to conduct electricity. They generally have high melting points.