Final answer:
The energy required to create bonds between two hydrogen molecules is measured in kilojoules, as the joule is the standard unit of energy in the International System of Units (SI).
Step-by-step explanation:
The energy needed to create bonds between two hydrogen molecules is measured in units of energy. In the International System of Units (SI), the unit of energy, work, and heat is the joule (J). Therefore, the correct answer is B. kilojoules.
Energy in the context of bond formation and breaking can also be expressed in calories, where one calorie is the amount of energy needed to raise the temperature of one gram of water by 1°C. However, when discussing energy in a scientific or chemical context, the joule is the standard unit of measurement. A kilojoule is simply 1000 joules. Considering the options provided and the fact that the joule is the standard scientific unit, the energy needed to create bonds between two hydrogen molecules is best measured in kilojoules.