Being a Chemist. Summary Sheets. Gleniffer High School

Transcription

1 Being a Chemist Summary Sheets Gleniffer High School 0

2 State that the light year is a measure of astronomical distance State the speed at which light travels Give examples of the relative distance between the Earth and other celestial objects By researching features of our solar system, I can use simple models to communicate my understanding of size, scale, time and relative motion within it. SCN 2-06a o The energy of a wave can be measured the method used to measure the energy is different for each type of wave. Water measure the height of the wave and/or flow rate of water You must be able to: state that the light year as a measure of astronomical distance state the speed at which light travels calculate how far a light year is give examples of the relative distances between the Earth and other celestial objects 1

3 By researching features of our solar system, I can use simple models to communicate my understanding of size, scale, time and relative motion within it. SCN 2-06a o Sounds are made by objects vibrating o Sounds can travel by cause particles close to them to vibrate o Solids, liquids and gases all contain particles and so sound can travel through them. Pupils must be able to state: the Sun is at the centre of our solar system the Earth is the third planet in our solar system the names of the planets in our solar system, in order from the Sun 2

4 By using my knowledge of our solar system and the basic needs of living things, I can produce a reasoned argument on the likelihood of life existing elsewhere in the universe. SCN 3-06a o Frequency is a measure of how many times an object vibrates per second o Frequency is measured in hertz (Hz) Pupils must be able to: describe what is meant by the term habitable zone state the conditions required on a planet in order for it to sustain life give a reasoned argument as to the likelihood of life on other planets 3

5 Having explored the substances that make up Earth s surface, I can compare some of their characteristics and uses. SCN 2-17a o Amplifiers are used to make sounds louder by increasing the energy of the sound wave o An amplified wave will have a higher amplitude (showing that it has more energy) but will have the same frequency 4

6 I can explain the use of radiation and discuss how this has impacted upon society and our quality of life. SCN 4-11b o The electromagnetic (EM) spectrum contains different types of waves o EM spectrum waves not need particles to transfer energy and so can travel through a vacuum o All waves in the EM spectrum travel at the speed of light million ms -1 faster than sound at 340 ms -1 o Only visible light is visible in the EM spectrum o The EM spectrum is made up of: Radio and TV Wave Microwaves Infra-red Visible light Ultraviolet X-rays Gamma rays 5

7 I can use my knowledge of different ways in which heat is transferred between hot and cold objects and the thermal conductivity of materials to improve energy efficiency in buildings or other systems. SCN 3-04a Heat is a form of energy Temperature is a measure of how hot or cold something is o Heat can come from natural sources such as the o sun or living things o Heat can come from artificial sources such as fires and heaters 6

8 By exploring radiations beyond the visible, I can describe a selected application, discussing the advantages and limitations. SCN 3-11b 7

9 By exploring radiations beyond the visible, I can describe a selected application, discussing the advantages and limitations. SCN 3-11b Conduction o Metals are good conductors of heat o The ability of a metal to conduct heat is known as thermal conductivity o Heat is transferred through a conductor as energy is passed from one particle to another o Some metals are better at conducting heat than others o A comparison of the thermal conductivity of different metals can be made using conductivity bars or a conductivity ring 8

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11 Cooling Down o Hot objects will release heat to cold objects o Heat loss can be measured by observing a change the temperature of a hot object over time o Cooling curves drawn from experimental results can be used to compare heat loss through different materials A fastest rate of heat loss Temp. C B cooling down more slowly C cooling but starting to level out time D temperature the same as room temperature 10

12 Convection o Heat travels through a fluid by convection o In convection particles become less dense as they are heated and rise in the liquid, as they rise colder particles sink o The movement of particles through a fluid as it is heated is known as a convection current o A convection current always starts upwards from a heat source 11

13 Radiation o Heat cannot travel through a vacuum by conduction or convection as there are no particles o Heat travels through a vacuum by radiation o Matt, black surfaces are the best at absorbing and emitting heat o Shiny, silver surfaces are the best at reflecting heat 12

14 I can use my knowledge of different ways in which heat is transferred between hot and cold objects and the thermal conductivity of materials to improve energy efficiency in buildings or other systems SCN 3-04 o Heat is lost in homes through conduction, convection and radiation 13

15 o There are many methods of reducing heat loss in the home such as: insulation, carpeting and double glazing o Pupils should be able to state at least two methods for reducing heat loss in the home and explain how they function. 14

16 By exploring reflections, I can use my knowledge of the properties of light to show how it can be used. SCN 2-11b o Light is a wave o Light is reflected from a mirrored surface 15

17 By exploring refraction of light when passed through different materials, lenses and prisms, I can explain how light can be used in a variety of applications. SCN 3-11a o Refraction is the change in speed of light when moving from one material to another o Light entering glass or plastic from air will slow down as glass is a more dense material o Refraction can cause the direction of light to change when moving from one material to another 16

18 o When white light goes through a prism it produces a spectrum of all the colours of visible light Red, Orange, Yellow, Green, Blue, Indigo and Violet (ROYGBIV) 17

19 Sight The cornea a protective layer over the front of the eye The iris changes size when light levels change The pupil a hole that allows light to enter the eye The lens helps focus rays of light onto the retina Muscles used to move the eyeball Retina - a screen containing light sensitive cells. Changes light energy into electrical energy Optic nerve carries electrical signals from the retina to the brain 18

20 Sight Defects o Short-sightedness means we can only see close objects clearly it is due to light focusing before the retina (caused by elongation of the eyeball) o Long-sightedness means that we can only see far away objects clearly it is due to light focusing after the retina (caused by thinning of the lens or lack of control in the eye muscles) o Concave lenses can be used to treat short sight o Convex lenses can be used to treat long sight 19

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