Answer:
The correct answer is - Swimmerets.
Explanation:
Swimmerets are small paddle-like appendages that are modified pairs of legs near the rare. or attached to the abdomen. These paddle-like appendages are help crabs to swim and also helps in carrying and aerating eggs.
These are present in lobster, and shrimps as well as swimming crabs. These are the modification of the legs of the crabs in order to better swimming and brooding of the eggs.
After the 1st half-life 250 g of the radioactive material will be left.
<span>After the 2nd half-life 125 g of the radioactive material will be left. </span>
<span>After the 3rd half-life 62.5 g of the radioactive material will be left. </span>
<span>Therefore after 60 minutes, 3 half lives would have occurred. </span>
<span>Therefore the half-life = 60 / 3 = 20 minutes when 250 grams of the original material would have remained radioactive. </span>
<span>Therefore the answer is A) About 250 gram of the material decayed in 20 minutes.</span>
