1. Atomic Structure Isotope
atomic# = p e- if neutral
Bohr Model ,8,18,32
atomic mass = mass# if rounded = p+ + n0
Isotope
-atoms of the same element -same # protons & electrons but neutrons differ -mass # on periodic table is an average

2. Isotopes 99% .8% .2% What is different about these carbon atoms?
carbon-12 carbon-13 carbon-14
Atomic Mass = fraction x mass (isotope 1) fraction x mass (isotope 2)
fraction x mass (isotope 3)
Average Atomic Mass
99% % %
Why is carbon 14 radioactive but not carbon 12 or 13?
n:p ratio (n>p, p>n, >84)
.:decay into new elements t1/2 5730yrs
.:carbon dating archeology