1. Island School Chemistry
3a-3d; 3h
COMPLETE THE FOLLOWING SHEETS AND UPLOAD TO YOUR BLOG
Revision sheet: Inside atoms!
Atomic Structure
You should fill in any missing words in the blank spaces!
The atom is the building block of all matter. Atoms are too small to be seen, even with
the most powerful light microscope.
The atom consists of as a small, dense positively charged nucleus surrounded by
orbiting electrons.
The nucleus contains protons, which have a positive charge, and neutrons, which
have no charge. Both of these particles have a mass of 1 unit on the atomic mass unit
scale.
Electrons move around the nucleus in shells (also known as energy levels). Electrons
have a single negative charge (the opposite of a proton) and almost no mass. (It takes
almost 2000 electrons to weigh the same as a proton or neutron.)
Find and paste a diagram of this
simple model of the atom in this box
Use the above information to complete the following table:
Particle Charge Mass
proton 1+ 1 unit
neutron no charge (neutral) 1 Unit
Electron -1 almost 0 (1/1840 units)
Atoms have no charge which means that the number of p (positive charges)
must equal the number of e (negative charges).
The number of protons in an atom is known as the ATOMIC NUMBER of that
atom. (This, of course, also equals the number of electrons in the atoms!)
Work through Absorb Chemistry ‘Inside the Atom’ using the link on ISLE

2. Island School Chemistry
3a-3d; 3h
Revision sheet: Electron arrangement in atoms
The electrons in an atom are in constant motion. They orbit the nucleus in shells or
energy levels. The electrons start filling up the shells from the inner shell outwards.
Each shell can only hold a certain number of electrons:
• The first shell, nearest the nucleus, can hold up to 2 electrons.
• The second and third shells can hold up to 8 electrons each.
The arrangement of electrons is called the electronic structure or electronic
configuration. For sodium, which has 11 electrons in its atom, the electron
structure can be written as 2,8,1 (or 2.8.1). The atoms may also be drawn using
circles to represent the shells and ‘dots’ (•) or ‘crosses’ (x) to represent the
electrons.
To do:
1) Go to ‘David Wizzy’s Periodic Table on ISLE. Click on ‘shell view’ and work through the
elements in order H, He, Li, Be ....etc watching the electrons orbiting the nucleus and
filling into shells.
2) Absorb Chemistry ‘Inside the Atom’ (link on ISLE)is also a useful source of information.
3) Draw diagrams (on file paper)to show the arrangement of electrons in an atoms of
Lithium, sodium, potassium, fluorine, chlorine and calcium
4) Scan diagrams and attach here

3. Island School Chemistry
3a-3d; 3h
g
Title: Valence Electrons (Electron Structure.)
Aim: Deduce the electronic configurations of the first twenty elements from their
positions in the Periodic Table. Deduce the number of outer electrons in a main group
element from its position in the Periodic Table
Questions: (Follow instructions and answer any questions)
1. Enter the ‘Multimedia Science program’ and find the ‘Chemistry’ section.
2. Click on activities by topic and then find ‘Bonding’.
3. Select the ‘Ionic Bonding’ topic.
4. Go to slide 2 and follow the instructions carefully on the bottom of the page. This
allows you to view the number of valence electrons in the outer shell.
How does this relate to the position in the periodic table?
5. How many valence electrons are there in an atom of Magnesium?
6. Select slide 3. Follow the instructions and answer the questions that appear on the
bottom of the page. You can also check your answers.
7. Find argon. How many valence electrons does it have? What group is it in? Does
this make it reactive or unreactive? Why?
8. Go to slide 4 and then play the game that allows you to predict the number of outer
valence electrons in different parts of the periodic table.
Extension: The chemical periods are the rows across the periodic table. How does the
electron structure tell us which chemical period an element is in? Give an example to
show this.
Key words: Outer electrons, valence electrons, electron structure, electron shell, full
outer shell, periodic table, groups, chemical periods, unreactive.

4. Island School Chemistry
3a-3d; 3h
Revision sheet: Atomic Shorthand
Each atom has its own unique ATOMIC NUMBER. The atomic number tells us
the number of protons in an atom. As atoms are neutral this is also equal to the
number of electrons in the atom.
The mass of the atom is all concentrated in the nucleus and is made up of protons
and neutrons. The mass of an atom is called the MASS NUMBER
Atomic Shorthand
Na
Fill in the missing numbers:
From this example, sodium has an atomic number of so must have
protons and electrons
Sodium has a mass number of Therefore, must contain a total of
protons and neutrons.
As sodium has protons, it must have neutrons to make
up its mass number of
Now work through Absorb Chemistry ‘Atomic Shorthand’ using the link on ISLE
23
11
MASS NUMBER = number of protons + neutrons
ATOMIC NUMBER = number of protons
(also equals the number of electrons in atoms)
Number of neutrons = mass number – atomic number
11
12 11
2
23
11 12
23

5. Island School Chemistry
3a-3d; 3h
Atomic Structure Questions
1.
Element Atomic Number Mass Number
oxygen 8 16
chlorine 17 35
gallium 31 70
zinc 30 65
tungsten 74 184
a) How many protons in an atom of oxygen? 8.
b) Where in the atom would the protons be found? The Nucleus..
c) How many neutrons in an atom of zinc? .35
d) Which element in the above table has the same number of protons & neutrons? . .oxygen
e) What is the electronic configuration of oxygen? 2,6
2. Fill in the missing numbers in the following table (letter a- h):
Symbol Atomic
number
Mass
number
Number of
protons
Number of
neutrons
Electron
arrangement
He 2 a)4 2 2 2
Na 11 23 11 b)12 2,8,1
P 15 31 c)15 d)16 2,8,5
Ca e)20 40 20 20 f)2 8 8 2
Cl 17 37 17 g)20 h)2 8 7
3. The element argon exists as single atoms. Use your Periodic Table to find out the following
information about Argon:
Atomic number: .. 18 Mass number:. 40
No. of protons:. . 18 No. of neutrons: . .
No. of electrons: . Electronic configuration . .2,8,8
4. Cl Calculate the number of protons, electrons and neutrons in this atom
Protons: . 18 Electron: . 17 Neutrons: .17
5. Complete the following table:
Name Relative charge Relative mass
proton a) +1 1
b)Neutron zero c) 1
electron Negative (1-) 1/1840
35
17

6. Island School Chemistry
3a-3d; 3h
Atomic Structure Questions
1.
Element Atomic Number Mass Number
oxygen 8 16
chlorine 17 35
gallium 31 70
zinc 30 65
tungsten 74 184
a) How many protons in an atom of oxygen? 8.
b) Where in the atom would the protons be found? The Nucleus..
c) How many neutrons in an atom of zinc? .35
d) Which element in the above table has the same number of protons & neutrons? . .oxygen
e) What is the electronic configuration of oxygen? 2,6
2. Fill in the missing numbers in the following table (letter a- h):
Symbol Atomic
number
Mass
number
Number of
protons
Number of
neutrons
Electron
arrangement
He 2 a)4 2 2 2
Na 11 23 11 b)12 2,8,1
P 15 31 c)15 d)16 2,8,5
Ca e)20 40 20 20 f)2 8 8 2
Cl 17 37 17 g)20 h)2 8 7
3. The element argon exists as single atoms. Use your Periodic Table to find out the following
information about Argon:
Atomic number: .. 18 Mass number:. 40
No. of protons:. . 18 No. of neutrons: . .
No. of electrons: . Electronic configuration . .2,8,8
4. Cl Calculate the number of protons, electrons and neutrons in this atom
Protons: . 18 Electron: . 17 Neutrons: .17
5. Complete the following table:
Name Relative charge Relative mass
proton a) +1 1
b)Neutron zero c) 1
electron Negative (1-) 1/1840
35
17