Atomic Structure Flashcards
Protons
charge = +1, mass = 1
Neutrons
Charge = 0, mass = 1
Electrons
charge = -1, mass = 0
To maintain a charge balance..
…the number of electrons equals the number of protons
Number of Protons =
Atomic number
Number of neutrons =
mass number - number of protons
number of electrons =
number of protons
drawing a diag = # of protons and neutrons in the center…
electrons on outer ring, first ring contains only 2, 8 electrons on each ring after
Isotope has..
of an element has the same atomic # (#protons), but different atomic mass.
hydrogen has three main isotopes:
hydrogen (protium), deuterium, and tritium
Protium (symbol H) has a natural abundance of 99.985%
this is the most common isotope. atomic mass = 1
Deuterium (symbol = D) has a natural abundance of 0.015%
this isotope is present in “heavy water” or D2O, commonly used as a neutron barrier in nuclear reactors. not radioactive. Atomic mass = 2
Tritium (symbol = T) not naturally occuring, radioactive
used to radioactively label DNA for drug and immunological studies. Atomic Mass = 3
once the atomic weights and the natural abundances are taken into account, the atomic mass for all hydrogen isotopes =
1.008
Protium =
1p, 0n, 1e