The answer is a I hope this helped
Answer:
= 28.745 g
Explanation:
Half life is the time taken by a radioactive element to decay by half the original amount.
Therefore;
New mass = Original mass × (1/2)^n
Where n is the number of half lives, in this case, n = 20/5.27 = 3.795
Therefore;
New mass = 399 g × (1/2)^3.795
<u> = 28.745 g</u>
<span>C-C and C-H bonds are relatively stable because
they have low bond dissociation energy
13. Dispersion forces are caused by the __________,
motion of electrons
Hope this answers the question. Have a nice day.</span>
Microscope, magnifying glass,