The Periodic Table
Twelve elements have been known since
ancient times.
What do you think they are?
(Name them, use your periodic table to
help you.)
The Periodic Table
Twelve elements have been known since
ancient times.
What do you think they are?
(Name them, use your periodic table to
help you.)
carbon, sulfur, iron, copper, arsenic, silver,
tin, antimony, gold, mercury, lead, bismuth
The Periodic Table
Why do you think these particular
elements have been known for so long,
while most elements were not discovered
until the 1800s and 1900s?
Overview of the Periodic Table
Metals
Metalloids
Nonmetals
Noble
gases
Overview of the Periodic Table
Metals
Metalloids
1. excellent heat
conductor
2. excellent
electrical conductor
3. lustrous (shiny)
4. malleable, ductile
5. silvery-gray,
except Cu and Au
6. solids at room T,
except Hg
Some properties of
metals, some
properties of
nonmetals
1. moderate
electrical
conductivity
2. appearance –
more like metals –
lustrous, silvery-gray
3. brittle like
nonmetals
4. solids at room T
Nonmetals
1.
2.
3.
4.
5.
6.
poor heat
conductors
poor electrical
conductors
not lustrous
brittle
variety of
colors
gases or brittle
solids at room
T
Noble
gases
1.
extremely
unreactive –
“inert”
2.
rarely form
compounds
with other
elements
3.
colorless,
odorless
gases at room
T
Trends of the Periodic Table
“periodic” = repeating pattern
Overall theme = electrons’ positions
relative to each other and the nucleus
determine the following properties:
4. Electron configuration
5. Ionic radius
Electron Configuration
Compare the charges on the ion list with the position
of the element in the periodic table
Electron Configuration
• Noble gas configuration = [core] e-’s
• ‘Outer’ electrons = valence e-’s
• Elements of groups 1A-8A have valence e’s in s and p orbitals
Periodic Trends
The position of a valence electron and the
ability to remove it from an atom are
related to
• the number of protons in the nucleus
• the extent to which the valence electron is
shielded from the positively-charged nucleus by
the negatively-charged core electrons
Isoelectronic Series
= a group of ions and atoms that have the same electron configuration
1. Draw the electron configuration of each of the following elements.
2. What ions will they form?
3. When ions, how many electrons does each have?
How many protons?
4. Predict the relative diameters of the members of this isoelectronic
series.
Isoelectronic Series
Element
Electron
config
Ion
O
F
Ne
Na
Mg
Prediction: smallest to largest:
Ion
# e-’s
Ion
# p+
Isoelectronic Series
Element
O
F
Ne
Na
Mg
Electron
config
Ion
Ion
# e-’s
Ion
# p+
1s22s22p4
 1s22s22p6
O2-
10 e-
8 p+
1s22s22p5
 1s22s22p6
F-
10 e-
9 p+
1s22s22p6
 1s22s22p6
Ne
10 e-
10 p+
1s22s22p63s1
 1s22s22p6
Na+
10 e-
11 p+
1s22s22p63s2
 1s22s22p6
Mg2+
10 e-
12 p+
Prediction: smallest to largest: Mg2+ < Na+ < Ne < F-< O2-
Reminder: Atomic Radius
Ionic Radius
• Cations (+) smaller than original
atom
– remove e-’s  greater pull from
nucleus
• Anions (-) larger than original atom
– Increased repulsion swells the shell
Ionic Radius
Ionic Radius
1. In this table of ionic radii, how is the charge of the ions of elements in
groups 1A-4A related to the group number?