Answer:
2.62 years
Explanation:
The half life of a material is the time taken for half of the number of radioactive atoms in a radioactive material to remain.
If a radioactive material is cut into pieces, each piece has the same half life as the whole material.
Hence, if Strontium-147 is cut into pieces, each piece will have a half life of 2.62 years, just as the whole material.
Answer:
A particle or packet of light.
Explanation:
A photon essentially doesn't have a charge and thus can't be called an electron. So, option 1 is incorrect.
Photons are in fact packets of electromagnetic energy that light is made up of. So, option 2 is correct.
A photon is not a gaseous mass that indicates the preliminary stage in a star's growth and thus can't be a protostar. So, option 3 is incorrect.
Photons having different energies are constituents of the electromagnetic spectrum and thus a single photon can't be a spectrum. So, option 4 is incorrect.