higher energy.

Which of two objects or ;substances has the higher energy. Explain the answer with reference to the ;capacity of each to do work and say whether the energy that distinguishes them is ;kinetic energy or potential energy.

a. (1) A methane molecule, CH4, in the stratosphere or (2) a CH3 molecule and a hydrogen atom formed from breaking one of the carbon‑hydrogen bonds in a CH4 molecule.

b. (1) A water molecule moving at 1.63 ×10^3 mi/h or (2) the same water molecule moving at 1.81 ×10^3 mi/h. (These are the average velocities of water molecules at 110 °C and 200° C.)

c. (1) Iodine solid or (2) iodine gas. (Assume that the two systems are at the same temperature.)

d. (1) A nitrogen monoxide, NO, molecule and an oxygen atom in the stratosphere or (2) the NO2 molecule that can form when they collide.