Btec – Chemistry 1
Lesson 1 – Group 1 Metals
Patterns in the periodic table
Starter Activity
• Use the white boards...
• In ONE minute name as many
chemicals as you can
What are we going to learn?
Essential...
•
What the periodic table is
•
That the position of an element in the periodic table
can provide information about its electronic structure
Merit grade...
•
That elements in groups have similar reactions
•
Be able to predict the reactions of elements in the
periodic table
Extension / Distinction...
•
Reactions of elements can depend on their electronic
structure
The periodic table
Task 1 (10 mins)...
In groups look at the periodic table,
1. Why is water not in the periodic table?
2. Look at the elements either side of the
black zig-zag line – what do you think
this line seperates?
3. Is there any pattern in the numbers that
are written by each element?
One person from each table can use
http://www.webelements.com/
to help...
Demonstration...
(Na, Li, K)
Element
Appearance Reaction
with water
Marks out
of 10
Na
Li
K
Rb
Cs
Fr
20 mins
We have looked
at Li, Na and K
Now make
predictions for
Rb, Cs and Fr
Watch DVD and
complete table...
Patterns in the periodic table
Reactivity
• Group 1 elements become more
reactive as you go down the group
• Make an annotation on your
worksheet
Watch introduction to periodic
table and answer questions...
Plenary...
• In groups – on your white board...
1. What is the periodic table?
2. Draw an outline of the Periodic table,
indicate a group and a period
3. What can you say about the reactions
of elements in a group?
4. Were there any mistakes in the DVD?
Extension...
• Use www.webelements.com to find
out about the reactions of group 7
elements.
• What sort of reactions take place?
• Are they similar or different?
Not in this lesson...
Patterns in the periodic table
• It is a bit like gravity
• The nucleus of an atom ‘pulls’ and
‘holds’ the electrons in orbit
around the nucleus
Patterns in the periodic table
• The bigger the atom gets, the
easier it loses an electron
Li
K
Pattern in the periodic table
• So potassium is more reactive than
lithium
• Francium is the most reactive as it is
the largest atom
Li
K
• The nucleus is further away, so the pull
is less
Pattern in the periodic table
• Group 7 elements become less
reactive as they go down the
group
• Why?
Pattern in the periodic table
• Again it is a bit like gravity
• The smaller the atom the easier it gains
an electron
F
Cl
Pattern in the periodic table
• So Chlorine is less reactive than
Fluorine
• Astatine is the least reactive in the
group as it has the largest atom and
the smallest ‘pull’
F
Cl
Pattern in the periodic table
• Group 8 has a full outer shell
• It does not want to lose or gain
electrons
• So they are very un-reactive
Ne
Ar
Boiling points
• The boiling points of group 1
decrease down the group
• The boiling points of group 7
increase down the group
Questions
1. What happens to the boiling point of the metals as you move down
group 1
2. Group 1 atoms want to loose an electron, do you think it would be
easier to remove an electron from Lithium or Cs?
3. What is the most reactive element in group 1?
4. Group 7 atoms want to gain an electron, which atom would most
strongly attract an electron to the ‘gap’ in the outer shell?
5. Which is the most reactive element in group 7?
6. Group 8 elements are unreactive, with reference to their electron
structure, why is this?
Structure
of the
Nucleus
What have we learnt?
We have learnt……
• That the location of an element in
the periodic table can provide
information about its electronic
structure
• That elements in groups have
similar reactions
• Reactions of elements can
depend on their electronic
structure
Structure of the Nucleus…
What the numbers mean…
• Big number – Atomic
Mass
Total number of bits
in the nucleus
• Small number –
Atomic Number
Number of protons in
the nucleus
What is the atomic mass?
What is the atomic number?
• Look at
your
periodic
tables…
• What atom
is this…
(the red ones are
protons)
Element
Atomic
number
Mass
number
Number
of
protons
Number
of
neutrons
Number
of
electrons
H
1
1
1
0
1
He
2
4
2
2
2
Li
3
7
C
6
N
6
14
O
7
8
Na
23
Mg
8
11
12
Cl
17
35
Cl
17
37
Cu
29
63
Cu
29
65
12
Isotopes
Name Protons
80
35
40
18
35
17
37
17
Br
Neutrons electrons
Isotopes…
• Isotopes are identical in their
chemical reactions.
• This is because they have the
same number of protons and the
same number of electrons.
• The uncharged neutrons make no
difference to chemical properties
but do affect physical properties
such as melting point and density.
Today's wonderful activities…
• Complete worksheet (Atomic
Structure)
• Applied science workbook
Questions (p.g. 14-15)
• Complete worksheet
Assignment
Assignment…
Scenario….
Produce a magazine article for a forensic science magazine.
Make a title page with …
• A title (e.g. ‘All about atoms’)
• A logo used on the title page and also every other page
• ‘South West edition’ or similar to show that it’s a local
periodical
• Date
• Price
For the article itself …
• text boxes can create columns of text just like a real article in
a newspaper or magazine.
• Pictures can be hand drawn onto printed sheets or students
can cut & stick what they already have
• Every page, including the title page must be numbered
Grading criteria P1
• Describe atomic and electronic
structures of elements 1-20,
including isotopes, in the
periodic table
Grading criteria M1
• Describe the patterns and
trends of chemical properties
of groups 1 and 7 in the
periodic table
Grading criteria D1
• Explain the patterns and
trends within groups 1 and 7
in the periodic table
In more detail…
Scenario…. Produce a magazine article
for a forensic science magazine. Make a
title page with …
A title (e.g. ‘All about atoms’)
• A logo used on the title page and also
every other page
• ‘South West edition’ or similar to show
that it’s a local periodical
• Date
• Price
P1
• Using diagrams, describe the atomic / electronic
structures of the first 20 atoms of the periodic table
• State the number of protons, neutrons and electrons
for each atom
• Define isotopes. Draw and describe the 2 atoms of
chlorine, showing the number of protons, neutrons
and electrons for each atom
M1
• Relate the number of electrons in the outer shells of
group 1 and 7 to their group number. Describe how
outer electrons are further from the nucleus as we
go down the group
• Describe patterns and trends in group 1
• Students write a description of the practical to
investigate the reactivity of group 7 elements
• Describe patterns and trends in group 7 from your
results
D1
• Explain patterns and trends in group 7 according to
their atomic structure
Page from Longman FND book 2 that will help…
P1 138
M
D
1
1
• Using diagrams, describe the atomic / electronic
structures of the first 20 atoms of the periodic table
136
• State the number of protons, neutrons and electrons for
each atom
137
• Define isotopes. Draw and describe the 2 atoms of
chlorine, showing the number of protons, neutrons and
electrons for each atom
140
• Relate the number of electrons in the outer shells of
group 1 and 7 to their group number. Describe how
outer electrons are further from the nucleus as we go
down the group
152
• Describe patterns and trends in group 1
153
• Students write a description of the practical to
investigate the reactivity of group 7 elements
156
• Describe patterns and trends in group 7 from your
results
• Explain patterns and trends in group 7 according to their
atomic structure
Example…
• Need a scanned example…