The scientist who proposed the 'plum pudding' model of the atom was: 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:
The strong nuclear force is the attractive force that binds protons and neutrons (nucleons) together in the nucleus, overcoming the electrostatic repulsion between protons. It is short-range and charge-independent. Electrostatic repulsion would otherwise blow the nucleus apart. Gravitational force is negligible at this scale. Van der Waals forces operate between molecules.

Explanation:
Sodium hydroxide (NaOH) has ionic bond between Na⁺ and OH⁻, and covalent bond between O and H within OH⁻. NaCl is purely ionic; CH₄ and HCl are purely covalent (polar covalent in HCl, but not ionic).