Half-life is a first-order reaction which means the rate of decay is constant. Using the supplied value of the half-life of 14c (5715 years), and that the <span>piece of ancient charcoal contains only 20% as much of the radioactive carbon as a piece of modern charcoal, the calculated "age" or timespan when the tree got burned is </span>13269.819062281 or simply, 13270 years ago.
2 atoms:
one mole is 6.022 times 10 to the 23 atoms according to Avogadro's Number, there are 2 Hydrogens in water, H20, so therefore 2 times 6.022 times to 10 to the 23 is your answer. O which means that ever molecule of water has 2 atoms of hydrogen (H) and one atom of oxygen (O)
