<prompt> True about Cobalt 60 is AENatural radioactive agentAt.wt.59Emits b and y-raysHalf life is 5.3 yrs.  <response>: A i.e. Natural radioactive agent Radium has longest half lifeQ 1622 years. It emits a, YraysQ and it decays to radon. P-32, Sr-90 Y-90 emits 3 paicles.Q Energy of radiation emitted by Co-60 is 1.173 MevQ; Ra-226 is 0.8 Mev; P-32 is 0.698 Mev; Cs-137 is 0.662 Mev and Ir-192 is 0.47 MevQ Cow is aificially made radeonucliodeQ produced by irradiating ordinary naturally occurring Co-59 with neutrons. Co-60 has atomic number-27, atomic weight 58.93Q, half life 5.3 yearsQ and emits both 3 and y raysQ. It is used in both teletherapy source of choice and brachytherapy but avoided in interstitial implantationQ. Naturally occurring radioactive nucleide elements belong to one of the 3 series ie 1. Uronium series; 2. Thorium series; 3. Actinum series Cobalt6O and Ir 192 are aificial isotopes 