Transcript 2 - Free Exam Papers

THE PERIODIC TABLE
© Boardworks Ltd 2001
Variety
• There are millions of substances in the world.
• All these substances are made from about 100
different building blocks called elements.
• These elements take a huge variety of forms:
From poison
gases like
chlorine
From reactive
metals like
sodium
to unreactive
metals like
gold
To the air
we breathe
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Properties of Elements
• In science the word properties means, what
the substance is like.
• E.g. Here are some properties of sodium:
–
–
–
–
Metallic
Highly reactive
Solid but melts easily
Low density (light)
• It would be really useful to be able to predict
properties of elements instead of having to
remember them!
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Atomic Number
• Scientists found that the properties of elements
seem to depend upon atomic number.
• Atoms contain three types of particles:
Particle
Charge Relative Mass
Protons
+1
1
Neutrons
0
1
Electrons
-1
0.0005
• Atomic number =
the number of
protons in an atom.
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Atomic Number and Electrons
• In elements the atoms contain equal
numbers of protons and electrons.
• It follows that for an element the atomic
number is equal both to the number of
protons and to the number of electrons.
Atomic Number
Fluorine
9 protons
9+
9
9 electrons
9-
F
10 neutrons 0
Total Charge 0
19
Symbol
Atomic Mass
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Atomic Number and Patterns
• When scientists arranged elements in
order of increasing atomic number (below)
they found patterns in the properties.
Reactive Metals
Reactive Gases
Unreactive Gases
H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K
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Activity
• Do similar elements occur at regular intervals?
Reactive Gases
Reactive Metals
H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Count the number of elements to get from one reactive metal
8
to the next?
Count the number of elements to get from one reactive gas to
the next?
8
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Putting Elements in a Table
• If we divide the elements up and arrange them
into a table we easily get patterns.
H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K
1
2
3
4
5
6
Cut here
And arrange these
strips below each
other
7
8
9
10
and here
11
12
13
14
15
16
17
18
19
and here
H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K
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Putting Elements in a Table
• When we rearrange the strips elements that are
similar go into the same columns.
H He
1
2
Li Be B C N O F Ne
3
4
5
6
7
8
9
10
Na Mg Al Si P S Cl Ar
11
12
Reactive Metals
14
15
16
17
18
19
Reactive Gases
He
Ne
Be B C N O F
Na Mg Al Si P S Cl Ar
K
Li
13
K
Unreactive Gases
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Putting Elements in a Table
• Carrying on building up the elements by
atomic number led to the creation of the
periodic table shown below.
H
He
Li Be
B C N O F Ne
Na Mg
Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ?
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Groups – Columns of Elements
H
Li Be
Na Mg
K Ca Sc Ti
Rb Sr Y Zr
Cs Ba La Hf
Fr Ra Ac Rf
Means in-between
Transition Elements
B C N O F
V Cr Mn Fe Co Ni Cu Zn Al Si P S Cl
Nb Mo Tc Ru Rh Pd Ag Cd Ga Ge As Se Br
Ta W Re Os Ir Pt Au Hg In Sn Sb Te I
Db Sg Bh Hs Mt ? ? ? Tl Pb Bi Po At
Group 0
Group 7
Group 6
Group 5
Group 4
Group 3
Group 2
Group 1
Downward columns are called groups.
He
Ne
Ar
Kr
Xe
Rn
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Periods – Rows of Elements
Rows of elements are called periods.
Period Number
1
2
3
H
Li Be
Na Mg
He
B C N O F Ne
Al Si P S Cl Ar
6
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
7
Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ?
4
5
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0
7
6
5
4
3
2
1
Gp
Activity
Pd
1
2
3
4
5
6
7
H
Li Be
B C N O F
Na Mg
Al Si P S Cl
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At
Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ?
What’s the group and Period?
K
C
Mg
Cl
He
Ne
Ar
Kr
Xe
Rn
Group 1
7
3
2 Period 4
4
2
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Missing Elements!
• Below the chemical symbol have been replaced by
atomic numbers. You will see some are missing
1
3
11
19
37
55
87
4
5 6 7 8 9
12
13 14 15 16 17
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85
88 89 104 105 106 107 108 109 110 111 112
2
10
18
36
54
86
Two further series of elements should go here but are
only shown on some Periodic Tables. They are called
the lanthanides and actinides.
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Patterns 1. Metals and Non-metals
• Metals are on the left and centre.
• Non-metals are mostly on the right
• In between are metalloids – these are like metals
in some ways and like no-metals in others.
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Patterns 1. Metals and Non-metals
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Activity
• Say whether these elements are metals, nonmetals or metalloids
Francium
(Fr)
Silicon (Si)
Cobalt
Scandium
(Co)
(Sc)
Krypton
(Kr)
Metalloid
Metal
Non-metal
Metal
H
Li Be
He
B C N O F Ne
Na Mg
Al Si P S
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po
Cl
Br
I
At
Ar
Kr
Xe
Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ?
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Physical State
• Physical state means – is it a solid, liquid or gas.
• There are only 2 liquid elements.
• Notice how most of the gases are on the far right.
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Physical State
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Activity
• Say whether these elements are solids, liquids
or gases.
Niobium
Krypton(Ba)
(Kr)
(Nb)
Bromine
Barium
Nitrogen
(Br)
(N)
H
Li Be
Liquid
Solid
Gas
He
B C N O F Ne
Na Mg
Al Si P S
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po
Cl
Br
I
At
Ar
Kr
Xe
Rn
Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ?
© Boardworks Ltd 2001
Patterns 2. Reactivity of Metals
• As a general, but not perfect, rule: the further to
the left and the further down the table - the more
reactive the metal is.
More Reactive
More Reactive
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Activity
• Which metal is most reactive?
K
Ba Ca
Potassium
Calcium
(Ca)
(K)or
ororBarium
Iron
Lithium
(Fe)
(Li) (Mg)
Ca
Copper (Cu)
Magnesium
(Ba)
H
Li Be
Na Mg
Al
K Ca Sc Ti V Cr MnFe Co Ni Cu Zn GaGe
Rb Sr Y Zr NbMo Tc Ru Rh Pd Ag Cd In Sn Sb
Cs Ba La Hf Ta W ReOs Ir Pt Au Hg Tl Pb Bi Po
Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ?
© Boardworks Ltd 2001
Patterns 3. Reactivity of Non-Metals
• This is more complicated.
• At the very end of the periodic table is the most
unreactive group of elements in the table.
• Apart from that – the further up and the further
right – the more reactive the non-metal.
More reactive
More reactive
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Activity
• Which non-metal is most reactive?
Neon
Fluorine
(Ne)
(F)or
orIodine
Chlorine
(I)(Si)
(Cl)
Carbon
Oxygen
(C)
(O)
or
Oxygen
Silicon
(O)
IO
F
He
B C
Si
N O F Ne
P S
Cl Ar
As Se Br Kr
Te I
Xe
At Rn
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Patterns and Electron Structures
• The physical and chemical properties of elements
are hugely influenced by the number and
arrangement of electrons in the atom.
• This is why patterns in properties are linked to
atomic number.
• If the atomic number increases by one it means that
the atom has one extra electron.
1
2
3
4
H
5
He
1
Li
4
Be
B
7
9
10
Atomic number = number of
protons
For atoms of an element it is
also = number of electrons
Each element has one more electron
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Patterns and Electron Structures
• The places where we start a new period is to
do with the arrangement of the electrons.
• It is the point at which electrons start
entering a new shell further from the
nucleus.
H
He
Li
Be
B
C
N
O
F
Ne Na Mg
Al
Si
P
S
Cl
Ar
K
1
2
3
4
5
6
7
8
9
10 11
12
13
14
15
16
17
18
19
Cut here
and here
and here
We shall look at these electron arrangements in
the next few slides.
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Patterns of Electron Arrangements
• We can imagine building up atoms by adding
protons, neutrons and electrons as we cross
the periodic table.
2
1
2,1
2,2
2,8,1
2,8,2
2,8,8,1
2,8,8,2
2,3
2,4
2,5
2,6
2,7
2,8
2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8
Sc Ti V Cr MnFe Co Ni Cu Zn
2,8,8,2
Electrons
in 1st shell
Electrons
in 2nd shell
Electrons
in 3rd shell
Electrons
in 4th shell
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Deducing Electron Arrangements
• Because electrons will fill up “shells” working
outwards from the nucleus.
• The periodic table can be used to work out the
electronic arrangements within atoms.
Group Number = number of outer
shell electrons (Except for Gp 0)
Period number
= number of shells
1
1 1 2
2 2,1 2,2
3 2,8,1 2,8,2
4 2,8,8,1 22
5 Rb Sr
6 Cs Ba
7 Fr Ra
0
3 4 5 6 7 2
2,3
2,4
2,5
2,6
2,7
2,8
2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Ac
Rf
Db
Sg
Bh
Hs
Mt
?
?
?
Atomic number (which can be obtained by counting boxes
starting with the top left ) = number of electrons
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0
7
6
5
4
3
2
1
Gp
Activity
Pd
1
2
3
4
5
6
7
H
He
B C N O F Ne
Al Si P S Cl Ar
Li Be
Na Mg
K Ca Sc
Rb Sr Y
Cs Ba La
Fr Ra Ac
Ti
Zr
Hf
Rf
V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Db Sg Bh Hs Mt ? ? ?
What’s the electron arrangement
2.8.2
2.4
2.8.8.1
Mg
C
Kl 2.8.7
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Arrangement of Electrons
1
2
3
4
5
6
7
8
1
2
3
The transition
metals
Click on action buttons to reveal how
electron configuration is built-up.
Skip this
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Electrons in Period 1
1
2
3
4
5
6
7
8
1
1
2
Skip this
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Electrons in Period 2
Elements in the second period contain 2 electrons in the first
shell (complete) and the second shell is completed one
electron at a time as you cross the period from left to right.
1
2
3
4
5
6
7
2,1
2,2
2,3
2,4
2,5
2,6
2,7
8
2
2,8
This atom is
special it has a
complete outer shell
Skip this
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Electrons in Period 3
Elements in the third period have complete first and second
shells. The third shell is completed one electron at a time as you
cross the period from left to right.
1
2
3
4
5
6
7
8
3
2,8,1 2,8,2
2,8,3
2,8,4
2,8,5
2,8,6
2,8,7 2,8,8
Skip this
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Group 1 Elements
1
1
1
2
2,1
3
Skip this
Group 1 elements have 1
electron in the outermost
shell which they lose in
chemical reactions.
The outer electron is
further from the nucleus
and so more easily lost
as you go down the
group.
This is why reactivity
increases going
downwards
2,8,1
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Group 2 Elements
In chemical reactions
metals tend to lose their
outer shell electrons to
form positive ions.
So, these elements all
form ions with a 2+
charge.
2
2,2
The further the outer shell
is from the nucleus the
more easily electrons are
lost.
Skip this
2,8,2
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Group 3 Elements
3
Metals lose their
outer electrons to
form ions. The
charge on the ion
produced by
Group 3 metals
will be +3.
Skip this
2,3
2,8,3
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Group 4 Elements
The elements at
the top of Group
4 are nonmetals. They
bond covalently,
i.e. by sharing
electrons with
another atom.
Skip this
4
2,4
2,8,4
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Group 5 Elements
The number of
electrons in the
outermost shell is
the same as the
group number.
They need 3 more
electrons to
achieve a full
electron shell.
Skip this
5
2,5
2,8,5
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Group 6 Elements
The atoms in Group
6 form negative ions
(2-) by the addition
of two extra
electrons. This
completes their outer
most shell.
Skip this
6
2,6
2,8,6
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Group 7 Elements
Group 7 elements
form 1- ions by the
addition of 1 extra
electron.
They are most
reactive at the top of
the group because
incoming electrons
are pulled into shells
that are closer to the
nucleus.
Skip this
7
2,7
2,8,7
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Group 0 Elements
The elements in
Group 8 (or 0)
have complete
outer shells.
They are very
unreactive and are
called NOBLE (or
inert) GASES.
Skip this
8
2
2,8
2,8,8
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Periodic Table and Reactivity
• The fact that in each group the number
of outer shell electrons is the same leads
to similar types of chemical reactivity.
– E.G. All group 1 elements react with water
to give hydrogen and an alkali.
• The fact that the outer shell electrons get
progressively further from the nucleus
leads to trends (patterns).
– E.G. Group 1 elements get more reactive as
you go down the group.
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Broad Types of Element
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In the Periodic Table elements are arranged in
order of?
A.
B.
C.
D.
Atomic mass
Atomic number
Density
Boiling point
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Neutral atoms of an element contain?
A.
B.
C.
D.
Equal numbers of protons and neutrons
Equal numbers of electrons and neutrons
Equal numbers of protons and electrons
Equal numbers of protons, neutrons and
electrons
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A vertical collection of elements in the
Periodic Table are called?
A.
B.
C.
D.
Groups
Periods
Columns
Gases
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A horizontal collection of elements in the
Periodic Table are called?
A.Groups
B.Periods
C.Rows
D.Gases
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In the Periodic Table gases occur?
A.
B.
C.
D.
On the left
On the left and middle
On the right and middle
On the Right
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In the Periodic Table metals occur?
A.
B.
C.
D.
On the left
On the left and middle
On the right and middle
On the Right
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The Group 7 Elements are also called?
A.
B.
C.
D.
The halogens
The transition elements
The alkali metals
The noble gases
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The Group 1 Elements are also called?
A.
B.
C.
D.
The halogens
The transition elements
The alkali metals
The noble gases
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In the Periodic Table metals get more reactive
going towards?
A.
B.
C.
D.
Top left
Top right
Bottom left
Bottom right
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Which of these electron arrangements could
be a noble gas?
A.
B.
C.
D.
2.1,
2.5
2.7
2.8
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Which of these electron arrangements could
be a halogen?
A.
B.
C.
D.
2.1,
2.5
2.7
2.8
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Teacher Resources
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THE PERIODIC TABLE
H
He
B C N O F Ne
Al Si P S Cl Ar
Li Be
Na Mg
K Ca Sc
Rb Sr Y
Cs Ba La
Fr Ra Ac
Ti
Zr
Hf
Rf
V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Db Sg Bh Hs Mt ? ? ?
© Boardworks Ltd 2001
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Ac
Rf
Db
Sg
Bh
Hs
Mt
?
?
?
© Boardworks Ltd 2001