Three half lives
The half life of a radioactive substance is the time taken for the substance to decay to half the original amount of radioactive material present in the sample.
Recall that radioactivity is the decay of a radioactive material releasing energy in the form of radiation.
After each half life, half of the original radioactive sample remains
Hence fraction of the substance left after three half lives is
N/No = (1/2)^3
Where N/No is the fraction of radioactive material left
N/No = 1/8
hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.
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