Download Atomic Structure - Science at St. Dominics

Chemistry
Atomic Structure
1 of 49
© Boardworks Ltd 2005
Atoms – the building blocks
All substances are made from very tiny particles called atoms.
.
The yellow blobs in this image are
individual gold atoms, as seen
through an electron microscope.
2 of 49
© Boardworks Ltd 2005
Elements – different types of atom
Each element is made up of just one type of atom,
Copper is an
element made up of
copper atoms only.
Carbon is an
element made up of
carbon atoms only.
3 of 49
© Boardworks Ltd 2005
How small is an atom?
Atoms are extremely small – they are about 0.00000001 cm
wide.
To make an atom the size of a football it would have to be
enlarged by about 3,000,000,000 times.
N
X3,000,000,000
If a football was enlarged
by the same amount it
would stretch from the
UK to the USA.
4 of 49
© Boardworks Ltd 2005
The Amazing Atomic Zoom
5 of 49
© Boardworks Ltd 2005
Inside an atom
Where are the electrons and nucleus found in an atom?
6 of 49
© Boardworks Ltd 2005
Even smaller particles
Scientists now know that atoms are actually made from even
smaller subatomic particles. There are three types:
proton
neutron
electron
7 of 49
© Boardworks Ltd 2005
Where are subatomic particles found?
The protons and neutrons are
found at the centre of the
atom - the nucleus.
The electrons orbit the
nucleus in layers called
shells.
8 of 49
© Boardworks Ltd 2005
Properties of subatomic particles
Particle
9 of 49
Mass
Charge
proton
1
+1
neutron
1
0
electron
almost 0
-1
© Boardworks Ltd 2005
Properties of subatomic particles
10 of 49
© Boardworks Ltd 2005
How many protons?
The number of protons in an atom
is known as its atomic number.
It is the smaller of the two numbers
shown in most periodic tables.
11 of 49
© Boardworks Ltd 2005
What’s the atomic number?
What are the atomic numbers of these elements?
12 of 49
sodium
iron
tin
fluorine
11
26
50
9
© Boardworks Ltd 2005
Atoms and electrical charge
An important feature of subatomic particles is their electrical
charge:
Particle proton neutron electron
Charge
+1
0
-1
Atoms have equal numbers of protons and electrons, which
means their overall charge is zero.
For example, fluorine:
9 protons
= +9
9 electrons
= -9
10 neutrons
= 0
Total charge = 0
13 of 49
© Boardworks Ltd 2005
Atoms have no overall electrical charge and are neutral.
This is because they have an equal number of protons
and electrons.
A carbon atom
14 of 49
© Boardworks Ltd 2005
How are electrons arranged?
The arrangement of electrons in these shells is called the
electron configuration.
1st shell holds
a maximum of
2 electrons
2nd shell holds
a maximum of
8 electrons
3rd shell holds
a maximum of
8 electrons
15 of 49
© Boardworks Ltd 2005
Calculating electron configurations
16 of 49
© Boardworks Ltd 2005
How many neutrons?
The bigger of the two numbers
tells the mass number.
Mass number is the number of protons
added to the number of neutrons
17 of 49
© Boardworks Ltd 2005
What’s the mass number?
What are the mass numbers of these elements?
18 of 49
sodium
iron
tin
fluorine
23
56
119
19
© Boardworks Ltd 2005
What’s the mass number?
How many neutrons in each of the following?
19 of 49
sodium
iron
tin
fluorine
23
56
119
19
© Boardworks Ltd 2005
Isotopes of chlorine
What do you notice about these atoms of chlorine?
20 of 49
17 protons
17 protons
18 neutrons
20 neutrons
17 electrons
17 electrons
© Boardworks Ltd 2005
Isotopes of carbon
What do you notice about these three carbon atoms?
21 of 49
6 protons
6 protons
6 protons
6 neutrons
7 neutrons
8 neutrons
6 electrons
6 electrons
6 electrons
© Boardworks Ltd 2005
What is an isotope?
Isotopes are atoms of the same element
that have the same number of protons but
different numbers of neutrons.
mass number is
different
atomic number is the
same
22 of 49
© Boardworks Ltd 2005
Isotopes of hydrogen
What are the atomic numbers and the mass numbers of each
of the following..
hydrogen
23 of 49
deuterium
tritium
1 proton
1 proton
1 proton
0 neutrons
1 neutron
2 neutrons
1 electron
1 electron
1 electron
© Boardworks Ltd 2005
Work out the number of protons and the number of
neutrons in the following cases:
• Carbon with an atomic number of 6 and a
mass number of 13
• Nitrogen with an atomic number of 7 and a
mass number of 14
• Carbon with an atomic number of 6 and a
mass number of 14
• Nitrogen with an atomic number of 7 and a
mass number of 15
24 of 49
© Boardworks Ltd 2005
Summarizing atomic structure
25 of 49
© Boardworks Ltd 2005
Properties of the nucleus and electrons
26 of 49
© Boardworks Ltd 2005
Discovery of atomic structure
27 of 49
© Boardworks Ltd 2005
Anagrams
28 of 49
© Boardworks Ltd 2005
Atomic structure word search
29 of 49
© Boardworks Ltd 2005
Multiple-choice quiz
30 of 49
© Boardworks Ltd 2005