Section 2.2
Learning Objectives
Know what the periodic table is and how the
work of Demitri Mendeleev contributed to its development.
Know the difference between atomic number
and atomic mass.
Be able to determine the number of protons,
What is the Periodic Table?
Periodic Table: a chart that organizes all of
What is the Periodic Table?
Even though there are only about 100
naturally occurring elements, the atoms of these elements make up the millions of
Fluorite = CaF
2Ca = Calcium
+
Sulfuric Acid = H
2SO
4H = Hydrogen
+
S = Sulfur
+
What is the Periodic Table?
The periodic table contains information
about the different elements that make up all the solids, liquids, and gases in the known
What is the periodic table?
In the 1800’s, chemists were aware of many
What is the periodic table?
Worksheet #7 - Organizing “Elements”
•
Organize the images into a
grid based on things they
have in common. (like colour,
shape, etc.).
•
Leave spaces in the grid to
predict any images you may
be missing.
•
Record your organization
Mendeleev and the Periodic Table
The elements
remained
disorganized until
the 1860’s when a
chemist named
Demitri
Mendeleev
developed an
organization
Mendeleev’s Two Major Contributions
Mendeleev’s Two Major Contributions
2. He
left empty spaces
in his periodic
table and
predicted new elements
Mendeleev’s Two Major Contributions
Mendeleev’s Two Major Contributions
This was very important because it gave
chemists elements to look for and
led to
Using the periodic Table
What is the Periodic Table?
Each box on the periodic table contains
information about one particular element. It
Example: Iron
Atomic Number
Equals the number of protons
(p+) in an atom of this element
Equals the number of electrons
(e-) in an atom of this element
**Atoms must have a net neutral charge. This means the # of
Mass Number: the rounded atomic mass. It tells you combined number of protons and neutrons.
Ex: Iron has a mass number of 56 because atomic mass of 55.8 rounds up!
Summary
# of protons = atomic number
# of electrons = atomic number (same as protons for an atom!)
# of neutrons = mass number – atomic number (see example below)
Neutrons Example (Iron)
Step 1: Find the mass number by rounding the atomic mass:
Iron’s atomic mass is 55.8 so the mass number is 56!
Complete Examples on Board
Example 2: Sulfur
Example 3: Only told that the atomic # is 12
Example 4: Given then # of e- (37) and # of n0
Recap:
Elemen t Symbol Atomi c # Atomic Mass Mass # # p+ # e
- # n0
Br
12
36
Lesson Objectives:
Be able to locate and list the properties of elements
belonging to the following groups on the periodic table: (i) metals (ii) non-metals
(iii) metalloids (iv) transition metals.
Know what periods and families are on the periodic
table
Be able to identify and list the properties of the
following chemical families:
Recap:
The Periodic Table arranges the known
(Not in notes)
Sodium and Potassium share many of the same
(Not in notes)
If scientists discovered new element that reacts with
YAY!
Time to get your very own
periodic table!!!
Correct Text Book Mistake
Page 50
Types of Elements and their
Properties
Types of Elements
Mendeleev identified three main
types of elements on the periodic
table:
1.
Metals
2.
Non-Metals
The image below shows where to identify each
type of element on the periodic table. You will
need to remember this!
Properties of Metals, Non-Metals and
Metalloids
These three types of elements are identifiable by their different properties
Properties of Metals, Non-Metals and
Metalloids
Know what Ductile and Malleable mean!
Element properties: Metals
(i) All solid except for Mercury (liquid)
(ii)Shiny
(iii)Malleable
(iv)Ductile
(v)Conduct electricity
Element properties: Non-Metals
(i) Solids, liquids and gases
(ii)Not shiny (dull)
(iii)Non-malleable (brittle)
(iv)Not ductile
(v)Poor conductors of electricity
(vi)Poor conductors of heat
Carbo n
Phosphoro us
What about metalloids?
Metalloids: (below table)
elements found along the “staircase”.
They have some properties of metals and some properties of non-metals.
Boron
Sample Metalloid Silicon
Not all metalloids have the same properties. Some are more like metals, others are more like
non-metals.
All solids Shiny
Brittle (like non-metal) Not ductile
Worksheet #9
Grouping the Elements: Periods
and Families
Recall that Mendeleev organized the elements
based on their properties, with elements that were similar being closer together on the
periodic table.
As he organized them he noticed patterns in
Grouping the Elements: Periods and
Families (Page 11 in notes)
Periods: horizontal rows on the periodic
Grouping the Elements: Periods and
Families (Page 11 in notes)
Families: Also called groups. They are groups
of elements arranged in vertical columns
numbered 1 to18. Elements in the same group share similar properties.
Important Chemical Families
You must be able to identify each of these
families on the periodic table.
You must be familiar with the properties
Alkali Metals (Group 1)
Properties
React strongly with both oxygen
and water.
Very soft metals (cut with knife)
Low melting points for metals (below 200oC)
Reactivity increases down the family
(K is more reactive than Na)
Alkaline Earth Metals (Group 2)
Properties
Less reactive than Alkali Metals
Produce bright coloured flames when
burned in air.
Transition Metals (Groups 3-12)
Not technically a chemical family
because they are spread out over several groups.
Found in the centre of the
periodic table
Grouped together because they
all have complex arrangements of electrons which allows
them to react in special ways.
Some similarities exist in each column (Ex:
Common Properties of Element Families
Halogens (Column 17) Properties
Highly reactive non-metals
Contains each state @ room temp:
Gases: F and Cl Liquid: Br
Solid: I
Other Facts
Reactivity increases going UP the
Common Properties of Element Families
Noble Gases (Column 18) Properties
Most stable elements (means they do not react)
All are naturally colourless and odourless gases They glow different colours when electricity is
Complete Questions 5 and 6 on Worksheet #9
When finished start Homework Questions for portfolio:
Discussion
What do you notice about the Atomic # and
Atomic Mass as you go across a period?
What do you notice about Atomic # and
Atomic Mass as you move down a Family?
So what pattern or patterns do we see for the
