Answer:
Let No be initial no of atoms
N = N0 / 2 after 1 half-life
N = N0 / 4 after 2 half-lives
So after 2 half-lives 20 of the 80 atoms remain
Answer:
Its simple! B The ball accelerates upward!♡♡
<span>fast-moving particles colliding with slow-moving particles</span>
