CHMB41H3 Chapter Notes - Chapter 1: String Vibration, Molecular Mass, Ionic Bonding
Document Summary
Amount of positive charge on proton = amount of negative charge on electron. Therefore, # of protons & # of electrons in uncharged atom must be same: electrons move continuously. 12 & 1. 11% have 7 neutrons giving them mass # of 13. These 2 different kinds of carbon atoms (12c and 13c) = isotopes. o o: carbon also contains trace amount of. C, which has 6 protons & 8 neutrons. This isotope of c is radioactive, decaying with half-life of 5730 years. (half- life = time it takes for one-half of nuclei to decay. ) As long as plant/animal is alive, it takes in as much 14c as it excretes/exhales. When it dies, however, it no longer takes in 14c, so 14c in organism slowly decreases. Therefore, age of substance derived from living organism can be determined by its 14c content: atomic weight = average mass of atoms in element.
