C) DNA or protein sequences of shared genes.
Answer: Hydrogen-3 or tritium as it is commonly called, has a half life of 12.32 years. If you start with 20 grams of it, how much will remain after 25 years? Ending Amount = Beginning Amount / 2 (time / half-life) Ending Amount = 20 / 2 (25 / 12.32) Ending Amount = 20 / 2 (2.0292) Ending Amount = 20 / 4.0818. Ending Amount = 4.8997 grams
Explanation:
Yes it is.
Carbon dioxide goes through plants, which they turn into oxygen. Humans and animals take in the oxygen and breathe out carbon dioxide. Then it repeats.