Question

write proton proton cycle.

Answer 1

The proton–proton chain reaction is one of the two (known) sets of fusion reactions by which stars convert hydrogen to helium. It dominates in stars the size of the Sun or smaller.[1] (The other reaction is the CNO cycle, a catalytic cycle, which theoretical models suggest is the dominant source of energy in stars more massive than about 1.4 times the mass of the Sun.[citation needed]) In general, proton–proton fusion can occur only if the kinetic energy (i.e. temperature) of the protons is high enough to overcome their mutual electrostatic or Coulomb repulsion.[2] In the Sun, deuterium-producing events are rare. Diprotons are the much more common result of proton–proton reactions within the star, and diprotons almost immediately decay back into two protons. Since the conversion of hydrogen to helium is slow, the complete conversion of the hydrogen in the core of the Sun is calculated to take more than 1010 (ten billion) years.[3]

Answer 2

proton cycle:-it is the chain of thermonuclear reactions that is the chief source of the energy radiated by the sun and other cool main-sequence stars is called proton cycle.Another name for proton cycle is Proton-proton reaction.