Skills Objectives for CHEM 1211 Exam 3 –Fall, 2008
Exam 3 covers textbook chapters 5, 6 (except sections 6-7 and 6-8), and chapter 7 sections 7-1
Chapter 5 – Atomic Structure
Be able to identify the three fundamental particles important in chemistry: the proton, the
neutron, and the electron. Know qualitatively their relative masses and charges (proton
and neutron are about equal in mass, but the electron is much lighter; charges are +1, 0,
and –1 respectively).
Be able to write and interpret the symbol for an element, showing the number of protons,
and the number of total nucleons, e. g.
C. (Note: the numbers should lie vertically on
top of one another, not offset as shown here for typographic reasons.)
Know what an isotope is, and how isotopes of a given element differ from one another
(same atomic number, but different atomic mass).
Know that the periodic table is organized according to atomic number (the number of
protons in the nucleus).
Know the definition of an atomic mass unit (amu), and how it relates (for an atom) to the
weight in grams of a mole of the element. Be able to calculate the mass of a single atom
of any element.
Be able to calculate the atomic weight or mass of an element, if the relative abundances
and atomic masses of all isotopes are specified. Be able to calculate the relative
abundances of isotopes if the atomic weight or mass of the element and the atomic
masses of all isotopes are specified.
Be able to calculate the frequency or the wavelength of electromagnetic radiation, given
the velocity of the radiation (the velocity of light, c = 3.00 x 10
m/s) and either the
wavelength or frequency, from the relationship c =
Be able to calculate the energy of a single photon using Planck’s equation, E = h
if the frequency or wavelength is specified. (h = 6.626 x 10
Joul s). Be able to calculate
the energy of a mole of photons (called an Einstein).
Know what the photoelectric effect is, and why the idea of quantized particles of light is
needed to explain the photoelectric effect.
Be able to identify the features of an absorption spectrum and an emission spectrum. Be
able to describe the processes that take place during the absorption and emission of light
by an atom. (In absorption, an electron is promoted from a well-defined lower energy
level to a well-defined higher energy level by absorbing electromagnetic radiation of a
specified energy. In emission, an electron which has been excited to a higher energy level
falls back to a lower energy level and emits electromagnetic radiation.) Be able to relate