Answer:
I think it's D
Explanation:
Don't take my word for it
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>
It depend some plants have the waxy layer because of their cuticles and to make sure the leaf doesn't dry out or to protect it againts the harmful sun rays when directly shined on its good to have sun but not too much. HOPE THIS HELPS
Answer:
i believe that the answer is 22,24,25,28
