these are the specification points you need to understand ......these are the specification points...
TRANSCRIPT
These are the specification points you need to understand from this work
Work through the slides and copy out information into your chemistry book
when asked to.
Any problems:e.shore@bishopchalloner,bham.sch.uk
Mass number and atomic number
• Objectives:
• To know the structure of the atom.
• To understand what the atomic and mass number tells us about an atom.
• To understand which number identifies an element.
• To be able to work out the number of protons, neutrons and electrons in an atom.
Starter
Can you answer the questions on the
next slide?
1. Where do you find most of the mass of the
atom concentrated?
2. Which sub-atomic particles do you find in the
nucleus?
3. Where do you find the electrons?
4. What is the charge of an electron?
5. Why do you know that atoms have the same
number of protons and electrons?
1. Where do you find most of the mass of the
atom concentrated?
in the nucleus
2. Which sub-atomic particles do you find in the
nucleus?
protons and neutrons
3. Where do you find the electrons?
They orbit the nucleus in shells
4. What is the charge of an electron?
-1
5. Why do you know that atoms have the same
number of protons and electrons?
because atoms have no charge
Mass number and atomic number
• Objectives:
• To know the structure of the atom.
• To understand what the atomic and mass number tells us about an atom.
• To understand which number identifies an element.
• To be able to work out the number of protons, neutrons and electrons in an atom.
Each element in the Periodic Table has two numbers:
Copy into your book
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What is mass number?
Electrons have a mass of almost zero, which means that the
mass of each atom results almost entirely from the number
of protons and neutrons in the nucleus.
mass number = number + number
of neutrons of protons
1413aluminium
43lithium
01hydrogen
neutronsprotonsatomsmass
number
27
7
1
It is the larger of the two numbers shown
in most periodic tables.
Copy into your book
Mass number and atomic number
• Objectives:
• To know the structure of the atom.
• To understand what the atomic and mass number tells us about an atom.
• To understand which number identifies an element.
• To be able to work out the number of protons, neutrons and electrons in an atom.
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The atomic number
Each element has a definite and fixed number of protons.
All the atoms of a particular element always contain the
same number of protons. For example:
Atomic number = the number of protons in
an atom. This number is unique to each
element and so identifies an element.
It is the smaller of the two numbers
shown in most periodic tables.
hydrogen atoms always contain 1 proton
carbon atoms always contain 6 protons.
If the number of protons changes, then the atom becomes
a different element.
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Atomic number = the number of protons in
an atom. This number is unique to each
element and so identifies an element.
It is the smaller of the two numbers
shown in most periodic tables.
If the number of protons changes, then the atom becomes
a different element.
Copy into your book
Mass number and atomic number
• Objectives:
• To know the structure of the atom.
• To understand what the atomic and mass number tells us about an atom.
• To understand which number identifies an element.
• To be able to work out the number of protons, neutrons and electrons in an atom.
What are the missing words?
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protons
neutrons
electrons neutral
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Fill in the missing numbers
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8 8 8
30 30 35
79 79 118
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mass
13
14
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Fill in the missing numbers
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35 35 46
20 20 20
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• Now have a go at filling in the below
worksheet (separate document).The
answers are after this slide.
Use this
information to
help you fill in
the sheet.
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• Answers
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Knowledge check
• Can you answer the following questions?
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Well done for completing week 5
chemistry.