What is a neutrino?
A neutrino is an electrically neutral elementary particle with a tiny mass and very weak interactions with matter.
How it works and what the evidence shows
Core idea There are three flavors associated with electrons, muons and tau particles. Neutrinos can change flavor while traveling, a phenomenon called oscillation that shows their masses are not all zero. Evidence and research They arise in the Sun, some decays and high-energy events. Because interactions are rare, large sensitive detectors are needed.
Uses and limitations
Why it matters Neutrinos reveal processes deep in stars and test particle physics. Most passing through a detector leave no trace. Common misunderstandings A neutrino is not a neutron: one is a fundamental lepton, the other is made of quarks. Saying neutrinos have no mass conflicts with oscillation evidence.