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Chapter 3 Chemical Periodicity and The Formation of
Simple Compounds
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
Groups of Elements
The Periodic Table
Ions and Ionic Compounds
Covalent Bonding and Lewis Structures
Drawing Lewis Structures
Naming Compounds in Which Covalent
Bonding Occurs
The Shapes of Molecules
Elements Forming More than One Ion
Topics to be emphasized in Exam 1
Chapter 3 Chemical Periodicity. Formation of
Simple Compounds. Molecular Structure.
Section 3.2
The Periodic Table
Section 3.3
Covalent Bonding
Section 3.3
Lewis Structures
Section 3.4
Shapes of Molecules
Section 3.2 Periodic Table
(1) Classic exemplar of the scientific process: Mendeleev
(2) Atomic mass and atomic number as atom identifiers
(3) Periodic properties along rows and down columns
Electronegativity (ability of an atom to hold electrons)
Chemical reactivity (kinds of reactions atoms undergo)
Valence (the number of bonds to other atoms)
(4) Underlying structure of the Periodic Table is the
electronic structure of atoms not their masses.
Dmitri Mendeleev
Biological Periodic Table
http://umbbd.ahc.umn.edu/
periodic/spiral.html
Alternate forms of the periodic table:
http://www.wou.edu/las/physci/ch412/alttable.htm
The Periodic Table
(1) The chemical and physical properties of the element are periodic
functions of their atomic masses.
(2) The chemical and physical properties of the elements are periodic
functions of the atom number (number of protons in the nucleus =
number of electrons in the neutral atom).
(3) The elements can be arranged in groups (columns) of elements
that possess related chemical and physical properties.
(4) The elements can be arranged in periods (rows) of elements that
possess progressively different physical and chemical properties.
The Table by groups
I
II
III IV V VI VII VIII
Groups of Elements in the Periodic Table
Eight Groups (the representative elements):
I. Alkali metals:
II. Alkali earth metals:
III. Boron family:
IV. Carbon family:
V. Nitrogen family:
VI. Chalcogens
VII.Halogens
VIII. Noble gases:
(H), Li, Na, K, Rb, Cs
Be, Al, Ca, Sr, Ba, Ra
B, Al, Ga, In, Tl
C, Si, Ge, Sn, Pb
N, P, As, Sb, Bi
O, S, Se, Te, Po
F, Cl, Br, I, At
(He), Ne, Ar, Kr, Xe, Rn
The Table by “kinds” of elements
The Table by “sizes” of atoms
The Table by atomic radius
The connection between the Periodic Table and atomic structure.
Valence electrons: The electrons which are furthest from the positive nucleus and
are most loosely held. These electrons determine chemical properties of elements
and molecules.
Periodic Table: The group number of the group of a column for the main group
elements in the periodic table is the number of valence electrons possessed by the
neutral atom = atomic number = number of protons in the nucleus of an atom.
Group number (GN for main group elements) = number of valence electrons
Valence electrons for elements 1-18
I
II
III
IV
V
VI
VII
1H
VIII
2He
3Li
4Be
5B
6C
7N
8O
9F
10Ne
11Na
12Mg
13Al
14Si
15P
16S
17Cl
18Ar
The Table by electron affinity (energy released when an
electron is added to an atom
Electronegativity and
electron affinity are two
key features which
determine the nature of
the chemical bond.
More later….