Unstable particles are subatomic particles that decay or transform into other particles over time. Muons, kaons, and hyperons are all examples of unstable particles. Muons are leptons that are heavier than electrons and have a half-life of 2.2 microseconds. Kaons are mesons that are composed of a strange quark and an up or down quark, and have a half-life of 10-8 seconds. Hyperons are baryons that are composed of three quarks, and have a half-life of 10-10 seconds.