(a) Hydrogen (6) Helium (C) Nitrogen (d) Oxygen 7. If atomic weight of nitrogen is 14.0067, what is the ratio of 15N [m = 15.001] to N [m = 14.0037]? (a) 0.0036: (b) 0.36:1 (C) 1:0.365 (d) 1:1 The amount of Cisotope in a piece of wood is found to be 1/6 of that resent in a fresh piece of 3.