Organic Chemistry I Notes 8.26.13
ATOM: contains a nucleus composed of protons and neutrons, surrounded by electrons in an
ATOMIC NUMBER (Z): the number of protons in an atom. All atoms of a given element will
have the same Z.
MASS NUMBER (A): the number of protons and neutrons in an atom.
ISOTOPES: atoms of the same element with different numbers of neutrons, but the same number
of protons. Different mass numbers.
Ex) H=hydrogen (p)
ATOMIC MASS UNIT (AMU): exactly 1/12 of the mass of 12C (1.66x10 kg)
ATOMI WEIGHT: average weighted mass of all naturally occurring isotopes’ atoms.
ELECTRON SHELLS: Electrons are arranged in shells, with varying levels of energy. They
work to separate opposite charges.
1 Shell: 2 electrons
2 Shell: 8 electrons
3 Shell: 18 electrons
MOLECULAR WEIGHT: sum of all weights of all atoms in molecule.
HEISENBERG: claims that it is impossible to know the position of e-
SCHRODINGER: the behavior of electrons in an atom can be shown by a wave equation, and
the solutions of wave equations are orbitals.
ORBITALS: the energy of the electrons and the amount of space between the outer shell
and the atom.
*s & p orbitals most important in ochem.
www.masteringchemistry.com. PEARSON, n.d. Web. 12 Sept. 2013.
. "Electron Configuration." - Chemistry Help. N.p., n.d. Web. 12 Sept. 2013.
GROUND STATE ELECTRONIC CONFIGURATIONS: