Answer:
Due to presence of a triple bond between the two N−atoms, the bond dissociation enthalpy (941.4 kJ mol
−1
) is very high. Hence, N
2
is the least reactive.
The phase of a substance at a temperature of 275 K or 1.85 degrees Celsius can be any of the three phases namely a solid, a liquid and a gas. This depends on the pressure where the substance is subjected. Also, the phase can be determined by a phase diagram where it shows the phase of a certain substance at a specific temperature and pressure.
Liquid 2 because the lower the density the more it floats and the higher the density the more it sinks. The order from top to bottom is liquid 2, liquid 3, liquid 1
Given a mole each for iron and magnesium, the number of atoms of each element is equal. Iron has a greater mass due to its greater molecular weight. The correct statement among the choices is D.
