What type of reaction occurs when two hydrogen atoms collide at high speed, combining together into a helium atom?
Alpha decay
Beta decay
Fission
Fusion
Explanation: fusion is a nuclear reaction in which smaller atoms fuse together to form heavier elements. This describes the fusion of hydrogen into helium.
Fusion occurs when two atoms slam together to form a heavier atom, like when two hydrogen atoms fuse to form one helium atom. This is the same process that powers the sun and creates huge amounts of energy—several times greater than fission.
