The Periodic Table and Periodicity

1
The Periodic Table and Periodicity
Part 2
2
In our last class . . .
We examined 4 different groups (or families) ?
the Alkalai Metals (Group 1) ? the Alkaline
Earth Metals (Group 2) ? the Halogens (Group
17) ? the Noble Gases (Group 18)
3
In our last class . . .
We also looked at 3 different classes of
elements ? the Lathanides and Actinides (4f, 5f
or the inner Transition Metals) ? the Transition
Metals (the d block, 3d, 4d, 5d, 6d) ? the
Metalloids (B, Si, P, As, Se, Te)
While the chemistry of the elements in the d and
f blocks is very rich we dont examine it much
more in this course. We devote much of our
attention to the s block (Groups 1 and 2) and the
p block (Groups 13 18). Yesterday we looked at
some interesting features of the metalloids, the
halogens and the noble gases, today we will
examine the rest.
4
Remember the Trends!
5
Remember the Trends!
What element is the easiest to ionize (make a 1
cation)? Which non-noble gas element is the
least metallic? Which is larger Chlorine or
Bromine? Which is more metallic, Pd or Pt?
Fr
Fluorine
Bromine
Platinum
6
Let's Talk Valence
In our upcoming unit on Chemical Bonding we will
only be examining the elements of the s and p
blocks. Therefore we need to address the new term
VALENCE. Valence refers to the number of
electrons an atom has in its outermost
layer. Furthermore the maximum number of valence
electrons an atom (remember just the s and p
blocks now) can have is 8. (Groups 1, 2, 13, 14,
15, 16, 17, 18)
Its the valence electrons that are used to bond
with other atoms.
7
Let's Talk Valence
Consider Be and O Be has e- configuration
1s22s2, because the highest energy level (n2)
has 2 electrons in it, we say Be has 2 valence
electrons. O has e- configuration 1s22s22p4,
because the highest energy level (n2) has 6
electrons in it, we say O has 6 valence electrons.
How many valence electrons does P have? Does Sb
have? Does As have? How many valence electrons
does Ga have? Does Al have? Does B have? What
do you notice?
Atoms of the same group have the same number of
valence electrons.
8
The Families
The Boron Family
Group 13 contains B, Al, Ga, In and Tl. Each
element has 3 valence electrons. Electronic
configurations of 2s22p1, 3s23p1 etc. Boron is a
metalloid, the rest are considered metals. The
elements of Group 13 typically form compounds
with H and the non-metals (light blue).
9
The Families
The Carbon Family
Group 14 contains C, Si, Ge, Sn, and Pb. Each
element has 4 valence electrons. Electronic
configurations of 2s22p2, 3p23p2 etc. Carbon
readily forms 4 bonds. This versatility is the
basis for its presence in living things. The
elements of Group 14 typically form compounds
with H and the non-metals (light blue).
Silicon (metal)
Silicone (polymer)
10
The Families
The Nitrogen Family
Group 15 contains N, P, As, Sb and Bi. Each
element has 5 valence electrons. Electronic
configurations of 2s22p3, 3p23p3 etc. Nitrogen
and the rest of Group 15 readily from 3 bonds (we
will examine in detail later). The elements of
Group 15 typically form compounds with H and the
non-metals (light blue).
The active medicinal ingredient in Pepto-Bismol
is bismuth. Based on the other metals in its
family and our it why is this weird?
11
The Families
The Oxygen Family
Group 16 contains O, S, Se, Te and Po. Each
element has 6 valence electrons. Electronic
configurations of 2s22p4, 3p23p4 etc. Oxygen and
the rest of the group readily form 2
bonds. Oxygen and Sulfur form bonds with other
non-metals but also readily with metals. When a
metal reacts with oxygen we use the term
oxidation.
Iron, Fe
Rust, Fe2O3
12
The Families
The Halogens
Group 17 contains F, Cl, Br, I and At. Each
element has 7 valence electrons. Electronic
configurations of 2s22p5, 3p23p5 etc. Group 17
usually only form 1 bond with another element.
These non-metals typically form compounds with
metals.
Table salt, NaCl
Fluoride, NaF or H2SiF6
13
Remember the Trends!
14
Your Assignment
Complete the Periodic Table Detectives Activity.
You may use your notes, your textbook or ask me
to flip to any slide in wither yesterday or
todays presentation.