The IUPAC name of the element with atomic number 118 is: MCQ with Answer and Explanation

Explanation:
Silver (Ag) is a noble metal below hydrogen in the reactivity series and does not displace H₂ from dilute acids. Mg, Al, Fe are above H and react: Mg + 2HCl → MgCl₂ + H₂. However, Al reacts slowly initially due to oxide layer. Copper also doesn't react. The reactivity series determines acid reactivity.

Explanation:
The critical temperature (Tc) is the temperature above which a gas cannot be liquefied, regardless of how much pressure is applied. Above Tc, the kinetic energy of the molecules is too high for intermolecular forces to hold them together in a liquid state, even under extreme pressure.

Explanation:
Hydrogen has a very high calorific value of about 141.9 kJ/g (higher heating value) or ~150 kJ/g approximate. This makes it an excellent fuel, though storage is challenging. Methane ~55 kJ/g, petrol ~47 kJ/g. Hydrogen fuel cells use it efficiently.