The radioactive element carbon-14 has a half-life of 5750 years. a scientist determined that the bones from a mastodon had lost 69.4% of their carbon-14. how old were the bones at the time they were discovered?

9595.8 years

Explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Expression for rate law for first order kinetics is given by:

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant  =100

x = amount decomposed or lost =

a - x = amount left after decay process= (100-69.4)= 30.6

Putting in the values:

Thus the bones were 9595.8 years old.

the answer for apex is "1 and 6"

i'd say that the moon rock is about 2.2 billion years old.