Download 02 Atomic Structure [ppt 1MB]

S2 Science
Atomic Structure
LEARNING INTENTION
• We are learning about atomic structure
SUCCESS CRITERIA
• I can state that all matter is made up of atoms and that
•
•
•
a substance that is made up of the same kind of atoms
is an element
I can describe the basic structure of an atom and state
the location and charge of the proton, electron and
neutron within the atom structure
I can state the relative masses of the proton, neutron
and electron.
I can explain what is meant by atomic number and state
that all elements are arranged in order of increasing
atomic number in the Periodic Table
SUCCESS CRITERIA
• I can state that the mass number is the number of protons plus the
•
•
•
•
number of neutrons present in an atom
I can use nuclide notation to present information about atomic and
mass numbers of atoms
I can explain what is meant by the term isotope
I can state that the electrons of an atom are arranged in energy
levels
I can state that an atom is neutral and explain why
Modern Atomic Theory
• All elements are made of identical tiny
particles called atoms.
• At first scientists thought atoms were solid
spheres.
Modern Atomic Theory
• All elements are made of identical tiny
particles called atoms.
• At first scientists thought atoms were solid
spheres.
• We now know that this is not true. Atoms
are made up of smaller particles called
protons, electrons and neutrons.
Modern Atomic Theory
• The protons and
•
neutrons are in the
nucleus.
The electrons orbit
around the nucleus
Modern Atomic Theory
Particle
Charge
Proton
Neutron
electron
Use Standard Chemistry p23
Mass
(amu)
Found
where?
Modern Atomic Theory
Particle
Charge
Proton
+1
Neutron
electron
Use Standard Chemistry p23
Mass
(amu)
1
Found
where?
nucleus
Modern Atomic Theory
Particle
Charge
+1
Mass
(amu)
1
Proton
Neutron
nucleus
0
1
nucleus
electron
Use Standard Chemistry p23
Found
where?
Modern Atomic Theory
Particle
Charge
+1
Mass
(amu)
1
Proton
nucleus
Neutron
0
1
nucleus
electron
-1
1/1840
Outside
nucleus
Use Standard Chemistry p23
Found
where?
Modern Atomic Theory
• The ATOMIC NUMBER is equal to
• The MASS NUMBER is
• The number of electrons in an atom is equal to
• The number of neutrons in an atom is equal to
Modern Atomic Theory
• The ATOMIC NUMBER is equal to the number of
•
protons in an atom
The MASS NUMBER is
• The number of electrons in an atom is equal to
• The number of neutrons in an atom is equal to
Modern Atomic Theory
• The ATOMIC NUMBER is equal to the number of
•
•
protons in an atom
The MASS NUMBER is the number of protons
plus the number of neutrons
The number of electrons in an atom is equal to
• The number of neutrons in an atom is equal to
Modern Atomic Theory
• The ATOMIC NUMBER is equal to the number of
•
•
•
protons in an atom
The MASS NUMBER is the number of protons
plus the number of neutrons
The number of electrons in an atom is equal to
the number of protons
The number of neutrons in an atom is equal to
Modern Atomic Theory
• The ATOMIC NUMBER is equal to the number of
•
•
•
protons in an atom
The MASS NUMBER is the number of protons
plus the number of neutrons
The number of electrons in an atom is equal to
the number of protons
The number of neutrons in an atom is equal to
the mass number – the number of protons
Modern Atomic Theory
• Nuclide notation can be used to show the
number of protons, neutrons and
electrons in an atom eg
Mass number
37
17
Atomic number
Cl
Modern Atomic Theory
• Atomic number = number of protons
• Number of protons = number of electrons
• Mass number = protons + neutrons
• Number of neutrons = mass number – atomic number
Modern Atomic Theory
37
17
Cl
• Number of protons =
• Number of electrons =
• Number of neutrons =
Modern Atomic Theory
37
17
Cl
• Number of protons = 17
• Number of electrons =
• Number of neutrons =
Modern Atomic Theory
37
17
Cl
• Number of protons = 17
• Number of electrons = 17
• Number of neutrons =
Modern Atomic Theory
37
17
Cl
• Number of protons = 17
• Number of electrons = 17
• Number of neutrons = 20
Modern Atomic Theory
Element
24
12
80
35
Atomic
number
Mass
number
19
40
protons electrons neutrons
Mg
Br
9
10
Modern Atomic Theory
Element
24
12
80
35
Mg
Atomic
number
Mass
number
protons electrons neutrons
12
Br
19
40
9
10
Modern Atomic Theory
Element
24
12
80
35
Mg
Atomic
number
Mass
number
12
protons electrons neutrons
12
Br
19
40
9
10
Modern Atomic Theory
Element
24
12
80
35
Mg
Atomic
number
Mass
number
12
protons electrons neutrons
12
12
Br
19
40
9
10
Modern Atomic Theory
Element
24
12
80
35
Mg
Atomic
number
Mass
number
12
24
19
40
protons electrons neutrons
12
12
Br
9
10
Modern Atomic Theory
Element
24
12
80
35
Mg
Atomic
number
Mass
number
12
24
19
40
protons electrons neutrons
12
12
12
Br
9
10
Modern Atomic Theory
Element
24
12
80
35
Atomic
number
Mass
number
protons electrons neutrons
Mg
12
24
12
12
12
Br
35
80
35
35
45
19
40
9
10
Modern Atomic Theory
Element
24
12
80
35
Atomic
number
Mass
number
protons electrons neutrons
Mg
12
24
12
12
12
Br
35
80
35
35
45
K
19
40
9
10
Modern Atomic Theory
Element
24
12
Atomic
number
Mass
number
Mg
12
24
12
12
12
Br
35
80
35
35
45
K
19
40
80
35
40
19
protons electrons neutrons
9
10
Modern Atomic Theory
Element
24
12
Atomic
number
Mass
number
Mg
12
24
12
12
12
Br
35
80
35
35
45
K
19
40
19
19
21
80
35
40
19
protons electrons neutrons
9
10
Modern Atomic Theory
Element
24
12
Atomic
number
Mass
number
Mg
12
24
12
12
12
Br
35
80
35
35
45
K
19
40
19
19
21
F
9
80
35
40
19
9
protons electrons neutrons
9
10
Modern Atomic Theory
Element
24
12
Atomic
number
Mass
number
Mg
12
24
12
12
12
Br
35
80
35
35
45
K
19
40
19
19
21
9
19
9
9
10
80
35
40
19
19
9
F
protons electrons neutrons
Arranging Electrons
Target Model
• The target model of an atom is a picture
that shows clearly how the electrons in an
atom are arranged in separate energy
levels.
Target Model Example
• An atom with 15
•
electrons
Only 2 electrons can
fit into the first
energy level.
15+
Target Model
• Only 2 electrons can
•
fit into the first
energy level.
8 electrons fit into the
next shell
15+
Target Model
• Only 2 electrons can
•
•
fit into the first
energy level.
8 electrons fit into the
next shell
The five remaining
electrons fit into the
third shell.
15+
Electron Arrangements
• An electron
arrangement is a
sequence of numbers
that says how many
electrons are in each
energy level of an
atom starting from
the inside and
working outwards.
15+
2,8,5
Electron Arrangements
• Li
• Na
•F
• Si
Electron Arrangements
• Li
• Na
•F
• Si
2,1
Electron Arrangements
• Li
• Na
•F
• Si
2,1
2,8,1
Electron Arrangements
• Li
• Na
•F
• Si
2,1
2,8,1
2,7
Electron Arrangements
• Li
• Na
•F
• Si
2,1
2,8,1
2,7
2,8,4
• The number of electrons in the outer shell
is the same as the group number.
Target Pictures
• A target picture of an atom shows clearly
how the electrons are arranged in the
separate energy levels.
Drawing Target Pictures
• Potassium
Drawing Target Pictures
• Potassium
19+
2,8,8,1
Drawing Target Pictures
• Sulphur
Drawing Target Pictures
• Sulphur
• The first 4
electrons in the
shell are unpaired.
Any further
electrons form
pairs.
16+
2,8,6
Isotopes
• Isotopes are atoms of the same element
but with a different mass number.
Isotope
63
29
65
29
Cu
Cu
protons electrons neutrons
Isotopes
• Isotopes are atoms of the same element
but with a different mass number.
Isotope
63
29
65
29
Cu
Cu
protons electrons neutrons
29
Isotopes
• Isotopes are atoms of the same element
but with a different mass number.
Isotope
63
29
65
29
Cu
Cu
protons electrons neutrons
29
29
Isotopes
• Isotopes are atoms of the same element
but with a different mass number.
Isotope
63
29
65
29
Cu
Cu
protons electrons neutrons
29
29
34
Isotopes
• Isotopes are atoms of the same element
but with a different mass number.
Isotope
63
29
65
29
protons electrons neutrons
Cu
29
29
34
Cu
29
29
36
Isotopes
• They have different mass numbers
because they have a different number of
neutrons.
Isotopes
• They have different mass numbers
because they have a different number of
neutrons.
Isotopes
• In the data book, the mass number of
each element is given as an average of all
the isotopes.
Isotopes
• In the data book, the mass number of
each element is given as an average of all
the isotopes.
• This is called the relative atomic mass
Isotopes
• In the data book, the mass number of
each element is given as an average of all
the isotopes.
• This is called the relative atomic mass
• It does not need to be a whole number
eg chlorine
• Chlorine has 2 isotopes
35
17
Cl
37
Cl
17
eg chlorine
• Chlorine has 2 isotopes
p =17
e =17
n =18
35
17
Cl
37
Cl
17
p =17
e =17
n =20
eg chlorine
• Chlorine has 2 isotopes
p =17
e =17
n =18
35
17
Cl
75%
37
Cl
17
25%
p =17
e =17
n =20
eg chlorine
• Chlorine has 2 isotopes
p =17
e =17
n =18
35
17
Cl
37
17
75%
Weighted average
Relative atomic mass
Cl
p =17
e =17
n =20
25%
(75 X 35) + (25 X 37) / 100
35.5