Question

If 8 g of a radioactive substance are present initially and 2 yr later only 4 g remain, how much of the substance will be present after 5 yrs?

Answer 1

Answer:

none

Step-by-step explanation:

8-4=4

if every 2 years, 4 gallons disappear

then every 1 year, 2 gallons disappear

meaning that by 5 years there will be no substance left.

(5*2=10)