If we start with 16 grams of a radioactive substance, how many would remain after three half lives

2g

Explanation:

A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.

So, we divide the 16g sample in half 3 times.

16 ÷ 2 = 8

8 ÷ 2 = 4

4 ÷ 2 = 2

There will be 2g of the radioactive sample remaining after three half lives.

(hope this helps can i plz have brainlist :D hehe)

with 5 seconds, no, but over time if the police car stays at 65m/s ad the speeding car stays at 60, then obviously yes, but the answer to your question would be, no.

hope this : )