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Section 2.2:
The Periodic Table and Chemical Properties
The Periodic Table
 The periodic table is
a chart that organizes
the elements
according to their
physical and
chemical properties.
Elements of the Periodic Table
 Although there are many versions of the periodic
table, most contain the following properties:
Symbol
22
Ti
Titanium
47.9
Atomic mass
Atomic number
Name
Periodic Table Properties – Atomic Number
 Atomic Number
 The number of protons in the nucleus.
 The number of electrons surrounding the nucleus.

The number of protons equals the number of electrons giving the atom a neutral
charge.
 Atomic numbers increase one by one through the
periodic table.
 Q: The atomic number of calcium (Ca) is 20. What can
you now say about a calcium atom?
Periodic Table Properties:
Atomic Mass & Mass Number
 Atomic Mass
 The average mass of the atoms of an element.

Written as a decimal number and is measured in amu.
 Mass Number
 The number of protons and neutrons in an atom of an
element.


It can be approximated by rounding off the atomic mass.
# of Neutrons = Mass Number – Atomic Number
 Q: How many protons, electrons, and neutrons does an
atom of Titanium contain?
Practice Question –
Complete the following chart by referring to the periodic table:
Element
Name
Symbol
K
Atomic #
19
Mass #
#
protons
electrons
22
226
61
201
hydrogen
#
39
18
Ra
#
neutrons
80
47
Organization of the Periodic Table
Groups of Elements (p.51)
 All elements in the periodic table can be classified as
either metals, n0n-metals, or metalloids.
Organization of the Periodic Table
Groups of Elements (p.51)
 What are 3 physical properties of metals, non-metals,
and metalloids?
Metals
Non-metals
Metalloids
Organization of the Periodic Table
Periods (p.52)
 The periodic table is divided into horizontal rows
called periods.
 Periods:
 Horizontal rows
 Numbered 1 to 7
 Q: What period is Nickel located? _____
 Q: How many elements are in period 1? _____
Organization of the Periodic Table
Chemical Family
 The periodic table is also divided into vertical columns
called chemical families.
 Chemical Family
 Elements have similar physical and chemical properties.
 Numbered 1 to 18.
 There are 4
well-known
chemical families:




Alkali metals
alkaline earth metals
halogens
noble gases
Organization of the Periodic Table
Chemical Family – Alkali Metals
 Alkali Metals (Column 1)
 Li, Na, K, Rb, Cs, Fr
 Highly reactive

The reactivity increases as you
go down the group.
 Are soft and can be cut with a
knife.
Organization of the Periodic Table
Chemical Family – Alkaline Earth Metals
 Alkaline Earth Metals (Column 2)
 Be, Mg, Ca, Sr, Ba, Ra
 Fairly Reactive – will burn in air if heated

Are often used in fireworks since they produce
bright flames
Strontium (Sr) - red fireworks
Magnesium (Mg) reacting to flame
Organization of the Periodic Table
Chemical Family – Halogens
 Halogens (Column 17)
 F, Cl, Br, I, At
 Non-metals
 Highly reactive


Fluorine is the most reactive while
Iodine is the least.
Astatine is very rare (not much is
known)
Organization of the Periodic Table
Chemical Family – Noble Gases
 Noble Gases (Column 18)
 He, Ne, Ar, Kr, Xe, Rn
 The most stable and unreactive elements
 At room temperature, they are colourless,
odourless gases.
Neon and Argon – used in light fixtures
Neon – glows in different colours
Organization of the Periodic Table
Transition Metals
 Transition Metals
 Metals
 Found in the center of the periodic table.
 These are NOT a chemical family since they are spread
over many columns.
 They are grouped together because of the arrangement of
their electrons (more on this later in the chapter…)
 Share many common physical properties (eg., malleable,
ductile, conductive, etc.)
 Q: Do you know which 3 transition metals are magnetic?
Section 2.2
 To review and test your knowledge of the periodic
table, we will:
 Play Periodic Bingo!
 Complete some questions!!
 Note: You will be having a TEST on all the material in
Unit 1 up to this point. That is, Ch 1 (Sections 1.1 to 1.3)
and Ch2 (Sections 2.1 and 2.2)