1. reaction of electrons

1. 202/1 – Know the principles of
electricity
Outcome 1.1 – Reaction of
electrons
Unit 202 Principles of electrical
science

2. Unit 202 summative assessment
June 2015 (TBC)
Unit 202 Principles of electrical
science

3. 1.1 Describe the reaction of electrons
when charged to form an electric
current
This session

4. Electron flow
CONVENTIONAL
ACTUAL

5. Molecules
Every known substance is
made of molecules.
Every molecule is made of
atoms.

6. Atom construction
Atoms consist of 3
different particles
Protons
Electrons
Neutrons

7. Atom construction
Each of these has a
different electrical charge
Protons ?????????????
Electrons
Neutrons

8. Atom construction
Each of these has a
different electrical charge
Protons positive (+ve)
Electrons ???????????
Neutrons

9. Atom construction
Each of these has a
different electrical charge
Protons positive (+ve)
Electrons negative (-ve)
Neutrons ???????

10. Atom construction
Each of these has a
different electrical charge
Protons positive (+ve)
Electrons negative (-ve)
Neutrons neutral

11. Atom construction
As neutrons play no part in
electricity at this level of
study, they can be
ignored from now on

12. Atom construction
Protons are at the centre of an atom with the
electrons orbiting around them.

13. Copper atom
Copper has 29 electrons orbiting 29 protons

14. Copper atom
But may look more like this:-

15. A conductor
A conductor has electrons far
away from the protons in the
nucleus of an atom.
These electrons are easily moved
from atom to atom and are
called valence electrons.

16. A conductor
Copper (29)

17. A conductor
Aluminium (13)

18. A conductor
Silver (47)

19. Atom attraction
A positive magnet will attract a negative magnet,
The closer they are, the stronger the attraction

20. Atom attraction
This is the same within an atom, the electron is
attracted towards the proton
The closer they are, the stronger the attraction

21. Atom attraction
In a copper atom, the single electron furthest
from protons has the least attraction

22. Atom attraction
This electron is easily moved from atom to atom
and is the flow of electricity.

23. Electron flow between
atoms

24.  https://www.youtube.com/watch?v=KprFTxjQA
oE
Video

25. IF…….
6,241,509,629,152,650,000
electrons flow
This equals one coulomb
If 1 coulomb flows in 1 second
this equals 1 amp
Measurement of electrical
current flow

26. six quintillion, two hundred
forty-one quadrillion, five
hundred nine trillion, six
hundred twenty-nine billion,
one hundred fifty-two million,
six hundred fifty thousand
In words

27. 1.1 Describe the reaction of electrons
when charged to form an electric
current ?
A current will flow when an electro
motive force is connected to a
complete circuit.
Consolidation

28. 1.2 Identify sources of an
electromotive force
1.3 Describe the effects of an
electric current
Chemical, magnetic, thermal.
Next session