Final answer:
Most of the energy released in a fusion reaction converting a pair of hydrogen isotopes to an alpha particle and a neutron is in the form of kinetic energy, with particles being expelled at high speeds.
Step-by-step explanation:
Energy Released in Fusion Reactions
When a fusion reaction converts a pair of hydrogen isotopes to an alpha particle (He) and a neutron, most of the energy released is in the form of kinetic energy. In such fusion reactions, such as the combination of deuterium (²H) and tritium (³H), the products of the reaction are hurled apart at high speeds due to the conservation of momentum. This release in kinetic energy contributes to the overall energy output of the reaction, leading to the extreme temperatures that characterize environments where fusion occurs, such as the core of the sun.
The process follows the equation: ²H + ³H → He + n. A mass loss occurs in this transformation, which indicates the conversion of mass into energy according to Einstein's mass-energy equivalence principle, E=mc². This energy manifests primarily as the kinetic energy of the resultant particles, in addition to other energy forms such as heat and light, but the dominant form is kinetic.