1. Reduction of Water byAlkali Metals
a. 2M(s) + 2H20(l) = 2 M+(aq)OH-(aq) + H2(g)
i. M =Alkali metals (Li, Na, K)
2. Balancing Equations and Molecular Mass
a. AMU = Sum of atomic masses in a molecule. The usual convention is to use the
average atomic mass found in the periodic table if more than on isotope is present.
Then the molecular mass is the same as the molecular weight or molar mass in
g/mole, which the mass of one mole (6.02*10^23) of molecules. For example, the
molecular mass of C8H18 is:
i. 8*12.01 + 18*1.008 = 114.22amu.
b. Molecular mass is conserved in chemical reactions.
3. Empirical and Molecular Formulas
a. Empirical Formula - The simplest formula for a compound that agrees with the
elemental analysis or the mass ratios of the atoms and gives rise the smallest set
of whole numbers of atoms.
b. Molecular Formula – The formula of the compound as a molecule; it may be an
integer multiple of the empirical formula.
c. Ex: The empirical formula of the molecule NO is also NO, but the empirical
formula of the molecule N2O4 is NO2, a form with the simplest reduction of
4. We can observe similar patterns of reactivity for many elements, which eventually led to
the creation of the Periodic Table.
a. First based on a mass ordering of the elements in rows according to reactivity
b. Alkali Metals – Column 1 metals, excluding hydrogen
c. Alkaline Earth Metals – Column 2 metals
d. Transition Metals – Columns 3 – 12 metals
e. Chalcogens – Column 16 metals
f. Halogens – Column 17 metals
g. Noble/Inert Gases – Column 18 metals
5. Properties of metals, semimetals, nonmetals
a. Metals i. High electrical/thermal conductivity
ii. Electrical resistance increases with increases temperature
iv. Nonvolatile and High-melting oxides, halides, and hydrides
b. Semi-Metals or Metalloids
i. Intermediate electrical and thermal