Essay about Atom and Causes Little Pollution

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Year 9 and 10 Science Summary
NOTE TO STUDENTS:
This is a brief summary of MOST points in the syllabus. You will need to rely on your own notes and your book as well to fill in any gaps.
5.6
5.6.1 a

Apply basic physical models, theories and laws to situations involving energy, force and motion
Waves can move energy from one place to another, but NOT matter.
There are two types of waves: Transverse eg light and Compression (longitudinal) eg sound.

5.6.1 b

5.6.1 c

5.6.3 a

Frequency: Number of waves produced per second
The speed of a wave can be calculated using the wave equation: speed = frequency × wavelength
Waves
Uses
Gamma rays
Treat cancer, radioactive source
X-rays
X-ray photographs to examine bones, metal objects for cracks, luggage at airports
Ultra-violet rays
Fluorescent tubes
Visible light
Lasers
Infrared rays
Remote controls in TV’s, cameras, satellites, telescopes
Microwaves
Microwave ovens, radar
Radiowaves
AM, FM radio
Electrical Symbols
These are the symbols for the different components used in constructing circuits. Circuit diagrams use these symbols to show how the components in a circuit are connected.
Component
Symbol
Globe
Switch
Ammeter
Voltmeter
Resistor
Resistor
Rheostat
Battery

1

5.6.3 b

A water circuit can be compared to an electric circuit. The pump is like a power source (e.g. battery), the water flowing is like the flow of electrons (current), the tap is like a switch, the meter to measure flow rate is like an ammeter the filter represents some form of resistance (e.g. light globe, resistor, heating element) and the gauge to measure difference in pressure is like a voltmeter.

5.6.3 c

Voltage (Potential difference) is a measure of the amount of electrical energy gained or lost by electric charge as it moves through a circuit.
Current is a measure of the amount of electric charge passing a particular point in an electric circuit every second. Resistance is a measure of how difficult it is for electrons to flow through part of a circuit.

5.6.3 d

Relationship: If the resistance is constant, as voltage increases, current increases.
Series Circuit
Parallel Circuit
- Only one pathway for electrons
- More than one pathway for electrons
- A turned off or broken bulb will not allow other
- You can turn one bulb off and the others still glow bulbs to glow
- Another globe does not make the others less bright
- An extra bulb makes the others less bright
- The current is not constant where it
- The current is constant at different points in the branches at different points circuit - The voltage is the same for different components
- The voltage is not the same for different in the circuit components in the circuit eg eg
Globes in Series
Globes in Parallel

2

5.6.4 a

Absorption is when light is absorbed (taken in) by an object and is not transmitted (passed through) or reflected
(bounced off) by an object. The colour an object appears depends on the colours that are not absorbed, but instead reflected into our eyes. eg green leaves absorb all colours except green which is reflected into our eyes.
Reflection is when light bounces off a smooth surface.
Angle of incidence = angle of reflection

Refraction is the change in direction of light due to its change in speed as it passes from one transparent medium into another. When light speeds up eg glass -> air, it bends away from the normal. When light slows down eg air -> glass, it bends towards the normal.

Scattering is when light bounces off too many objects and they spread out into many different directions

5.6.5 a

Property
Everyday situations of where it occurs
Absorption
Pigments in paint
Reflection
Mirrors, optical fibres
Refraction
Lenses, pools which make things look shallow
Scattering
Appearance of a blue sky during the day and red during sunsets
Energy which is released from the nucleus of an atom is called nuclear…