Which is more stable a free neutron or free proton?

A free neutron is unstable, decaying to a proton, electron and antineutrino with a mean lifetime of just under 15 minutes (879.6±0.8 s). This radioactive decay, known as beta decay, is possible because the mass of the neutron is slightly greater than the proton. The free proton is stable.

How long does a proton live?

Experiments say the proton lifetime has to be greater than about 1034 years: That’s a 1 followed by 34 zeroes. For reference, the universe is only 13.8 billion years old, which is roughly a 1 followed by 10 zeros. Protons on average will outlast every star, galaxy and planet, even the ones not yet born.

Why is a free proton stable?

According to the Standard Model, the proton, a type of baryon, is stable because baryon number (quark number) is conserved (under normal circumstances; see chiral anomaly for exception).

Is a free proton stable?

A free proton is virtually stable but a free neutron is comparitively very UNstable. It will decay with a half-life of about 10.3 minutes but it is considerably more stable if combined into a nucleus. It decays as beta decay with the emission of an electron and an electron antineutrino.

Why are protons so stable?

According to the Standard Model, the proton, a type of baryon, is stable because baryon number (quark number) is conserved (under normal circumstances; see chiral anomaly for exception). Quantum tunnelling may be one of the mechanisms of proton decay.

Do Atoms last forever?

Ultimately, even these stable atoms have a limit imposed by the lifetime of proton (>1025 years). Remember, though, that the best estimate of the present age of the universe is the much smaller number of 1010 years, so for all practical purposes, atoms are forever.

Why can neutrons decay when they are free but not when they are inside a stable nucleus?

In stable nuclei the possible lower energy states are all filled, meaning they are each occupied by two protons with spin up and spin down. The Pauli exclusion principle therefore disallows the decay of a neutron to a proton within stable nuclei.

Why does a neutron turn into a proton?

Protons and neutrons consist of fundamental particles called quarks. A down quark within the neutron transforms into an up quark, changing the neutron into a proton (and changing the atomic element as a result).