Answer:
1
Step-by-step explanation:
X = 8.5 because 8.5 x 2 = 17 and 17 + 1 = 18
Answer:
that one of course
Step-by-step explanation:
its THAT one
Answer:
A. 2.8 billion years old
Step-by-step explanation:
1/16 = (1/2)^4, so 4 half-lives have elapsed.
4 · 0.700 billion years = 2.8 billion years
The rock is 2.8 billion years old.