Project Name: Chemical and Physical changes
Chemical and Physical changes occur around us in day-to-day life, in our surroundings. Understanding them will help us better understand our world.
1. CHANGE
Any change in the scientific mosaic, i.e. a transition from one accepted theory to another or from one employed method to another. (Source: Scientific Change - Encyclopedia of Scientonomy) .
It can be of two types:
1. Chemical Change
2. Physical Change
CHEMICAL CHANGE:
Change in shape and size of a substance by forming a new substance with new properties.
The new substance formed cannot be turned back into its original state.
PHYSICAL CHANGE:
Change in shape and size of a substance that does not alter the properties of a substance.
A substance formed may be turned back into its original state.
Fact: The burning of the candle represents both physical and chemical change. As it melts physically it changes its states, while chemically CO2 (a gas) release during the burning of the candle.
Project Name: Chemical and Physical changes
Chemical and Physical changes occur around us in day-to-day life, in our surroundings. Understanding them will help us better understand our world.
1. CHANGE
Any change in the scientific mosaic, i.e. a transition from one accepted theory to another or from one employed method to another. (Source: Scientific Change - Encyclopedia of Scientonomy) .
It can be of two types:
1. Chemical Change
2. Physical Change
CHEMICAL CHANGE:
Change in shape and size of a substance by forming a new substance with new properties.
The new substance formed cannot be turned back into its original state.
PHYSICAL CHANGE:
Change in shape and size of a substance that does not alter the properties of a substance.
A substance formed may be turned back into its original state.
Fact: The burning of the candle represents both physical and chemical change. As it melts physically it changes its states, while chemically CO2 (a gas) release during the burning of the candle.
Malaysia SPM syllabus Form 5 Physics Chapter 7. Part 1: Electric fields and Charge Flow.
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1. Friction and the Electrostatic Series
The simplest way to charge a neutral object
is by friction.
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2. Friction and the Electrostatic Series
Charging by friction is the transfer of e-
between 2 neutral objects that occurs when
they are rubbed together or touch.
Neutral Cotton
+- Neutral Ebonite
+-+-+ +-
-+-+- +-
+-
+-
3. Friction and the Electrostatic Series
When rubbed together, different materials
lose or gain e- more easily than others.
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4. Friction and the Electrostatic Series
The Electrostatic Series ranks different materials
on their ability to gain or lose electrons.
Tendency to gain
Material Relative Charge
electrons
platinum, gold most likely Negative −
rubber
ebonite
carbon, copper,
nickel
polyethylene
(plastic)
cotton
silk
nylon
fur or hair
wool
Glass least likely Positive +
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Acetate
5. Friction and the Electrostatic Series
Neutral Cotton Neutral Ebonite
+-
+-+-+ +-
+-
-+-+- +-
+-
What will happen when these are rubbed
together?
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6. Friction and the Electrostatic Series
Neutral Cotton
Rub
Rub Rub
+-+-+
Neutral Ebonite
-+-+ - +-
+- Rub
+-
Rub +-
+-
Rub
7. Friction and the Electrostatic Series
Neutral Cotton
Rub
Rub Rub
+-+-+
Neutral Ebonite
-+-+ - +-
+- Rub
e move from
-
+-
cotton into Rub +-
ebonite. +-
Rub
8. Friction and the Electrostatic Series
Results:
Positively
Charged Negatively
Cotton +- Charged Ebonite
-+
+++ -+
--
-+-+ +-
+-
-
* The number of + and – are conserved.
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9. Friction and the Electrostatic Series
Note: the + and − signs do not represent the
actual number of positive and negative charges
(protons or electrons).
They represent a collection of charges (protons or
electrons).
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