You have 960 grams of a radioactive kind of yttrium. How much will be left after 30 hours if

its half-life is 10 hours?

You will have 120g Yttrium remaining

Step-by-step explanation:

Since the half life is 10 hours, and you are required to find out the remaining amount after 30 hours, you can do 30 / 10 = 3.

Yttrium undergoes its half life 3 times in 30 hours.

What you can do is divide the original amount by 2 thrice.

960/2 = 480 (1st half life)

480/2 = 240 (2nd half life)

240/2 = 120 (3rd half life)

You will have 120g Yttrium remaining