The enthalpy change of atomisation is which type of process?

The enthalpy change of atomisation is which type of process?

• A. Endothermic
• B. Exothermic
• C. Isothermal
• D. Isobaric

Answer: (A)

The main idea is that bond breaking requires energy. Atomisation turns a mole of molecules into gaseous atoms, so all bonds are broken and energy must flow into the system to overcome those interactions. This makes the enthalpy change positive, so the process is endothermic. Terms like isothermal or isobaric describe the conditions of a process (constant temperature or constant pressure), not the direction of heat flow, so they don’t define the atomisation enthalpy.

The main idea is that bond breaking requires energy. Atomisation turns a mole of molecules into gaseous atoms, so all bonds are broken and energy must flow into the system to overcome those interactions. This makes the enthalpy change positive, so the process is endothermic. Terms like isothermal or isobaric describe the conditions of a process (constant temperature or constant pressure), not the direction of heat flow, so they don’t define the atomisation enthalpy.