Answer:
There will be 18 grams left after 12 hours.
Step-by-step explanation:
Half-life is the amount of time it take for a cell to turn from one condition to another.
To find the amount of grams for the first 6 hours.
72 ÷ 2= 36
Now, since 6 x 2 = 12, we need to divide 36 by 2 to find the next half-life.
36 ÷ 2 = 18
Therefore, there will be 18 grams left after 12 hours.
Hope this helps! :D