Cement is a mixture of: MCQ with Answer and Explanation

Explanation:
Electron affinity is the energy change when an electron is added to a neutral gaseous atom. It represents the tendency to gain electrons. Ionization energy is the energy to remove an electron. Electropositivity and metallic character relate to the tendency to lose electrons and form positive ions.

Explanation:
Burning of magnesium ribbon produces a new substance, magnesium oxide (MgO), and releases heat and light, which are indicators of a chemical change. Melting, dissolving, and boiling are physical changes because the chemical composition remains unchanged. Chemical changes are generally irreversible.

Explanation:
Oleum, also known as fuming sulfuric acid, is a solution of sulfur trioxide (SO3) in concentrated sulfuric acid (H2SO4). Its chemical formula is often represented as H2S2O7 (disulfuric acid or pyrosulfuric acid), which is essentially H2SO4 + SO3. It is an intermediate in the Contact process.