Subject Specific Targets 1.3.1 Single Award

BEFORE Unit

I have LEARNE

D

I understand the main parts of the electromagnetic spectrum including gamma rays, X-rays, ultraviolet, visible light, infra-red, microwaves and radio waves; the arrangement and scale of the electromagnetic spectrum in terms of frequencies, wavelengths and energies.I am able to name the 7 regions of the electromagnetic spectrum. Have knowledge of the order in which the regions are arranged in terms of wavelength, frequency or energy. In a question – speed of light will be given if needed.I know the relationship between the speed, frequency and wavelength of electromagnetic spectrum waves:

wave speed = frequency × wavelengthBe aware of the units kHz, MHz, SI multipliersI understand how theories about the Universe have changed over time to include the Steady State theory and Big Bang; differences in the two theories with reference to expansion of the Universe in the Big Bang theory; the Big Bang in which the Universe is believed to have started about 13.5 thousand million years ago; how evidence from red shift

1

Applied Single Award & Entry Level

WJEC ‘Entry Level’ taught in conjunction with content from Applied Single Award Science – to allow access to WJEC

Double Award Science GCSE.Applied Context In this section learners will explore the changing Universe. Scientists use

many different techniques to observe and search for patterns in the Universe in an attempt to understand and gather evidence concerning how it began, what it is now like, and how it is

changing. Learners can apply their knowledge in a number of fields including communications and space exploration.

Please note:

Some of the tasks and questions that you are expected to complete will not be in this booklet.

You will need to bring the following to each of your lessons:

exercise book pen, pencil, ruler, rubber and calculator.

Name: ___________________________________Class: ___________________________________Teacher: _________________________________1.3.1

‘Our place in the Universe’Target Sheet: (dual)

Applied Single Award & Entry Level WJECSingle Award = 1.3.1 “Our place in the Universe”

Entry Level = 1.3.1 “Our planet in the Universe”

and Cosmic Microwave Background Radiation (CMBR) is consistent with the Big Bang theory. Students should understand and describe the origin of CMBR and why the radiation is in the microwave region of the spectrumThe wavelength of the early radiation in the form of short wavelength radiation (gamma rays) has become longer wavelength (microwave) radiation that presently pervades the Universe. This change (increase) in wavelength is believed to be due to the expansion of space. Be aware of diagrams showing line spectrums and how these change for galaxies moving at different rates. I know how images of the universe are taken by Earth based systems, and space craft and transmitted to Earth; how electromagnetic waves are used to study structures in the universe e.g. • X-ray images of stars • ultra violet images of the Sun, galaxies and the planets • visible light images of the Sun, the planets, moons and galaxies • infra-red images of the Sun, the planets and the Milky Way • microwave images of the Sun and Cosmic Microwave Background Radiation (CMBR) • radio wave images of stars • images of black holesI understand the relative scale of the Universe, galaxies, and solar systems in terms of light years. Understand the difference in size of objects in the Universe. Recall that one light year is the distance that light will travel in 1 year.

Subject Specific Targets 1.3.1 Single Award

BEFORE Unit

I have LEARNED

I am aware of absorption spectra to include how they are produced and provide information about stars and galaxies (composition and relative movement).I understand the structure of our solar system to include the Sun, planets (rocky planets, gas giants, and dwarf planets), main moons, the asteroid belt, comets and the Oort Cloud.I am able to recall the order of the planets including the position of the asteroid belt. Know which planets are rocky and which are gaseous and know that the asteroid belt comprises many rocky asteroids and dwarf planets. Appreciate that comets have highly elliptical orbits, passing far out of our solar system. Also appreciate that most of the planets, including some dwarf planets, have moons which orbit them.I know about the Sun’s relative size and mass to the Earth. I know that nuclear fusion is the source of solar energy. I know about: Sun spot & solar flares and their effect on Earth (e.g. on telecommunications).I can interpret data to identify patterns and compare objects in the solar system (e.g. mean surface temperature, period of rotation, length of day, distance from Sun).

Subject Specific Targets 1.3.1 Entry LevelI understand that ‘EMS’ is short for “Electromagnetic Spectrum”I can name the main parts of the EMS including gamma rays, X-rays, ultra-violet, visible light, infra-red, microwaves and radio waves. I can name the 7 regions of the electromagnetic spectrum.I can arrange the EM spectrum in the correct order.I understand how electromagnetic waves are used to study the Solar System to

2

include:• X-ray images of the Sun • ultra-violet images of the Sun, galaxies and the Earth• visible light images of the Sun, planets, moons and galaxies• infra-red images of the Sun, the Earth and the Milky Way• radio-wave images of stars*I know the relative scale of the Universe, galaxies, and solar systems in terms of light years.*I understand the difference in size of objects in the Universe.*I can recall that one light year is the distance that light will travel in 1 year.*I understand the structure of our Solar System to include the Sun, planets, main moons, and the Asteroid Belt.*I can recall the order of the planets including the position of the asteroid belt.*I know which planets are rocky and which are gaseous. *I can appreciate that most of the planets have moons which orbit them.

THE ELECTROMAGNETIC SPECTRUMThe Electromagnetic spectrum (EMS) is a range of wavelengths and frequencies which extend from gamma rays to radio waves. The EMS is very useful because it allows us carry out a wide array of tasks, including letting us see very far into the universe and show us things which might not be visible to the naked eye.There are 7 parts of the electromagnetic spectrum. You need to remember the order:

This mnemonic will help you to remember the order:-

All E.M. waves have the same properties: Travel at the speed of light through a vacuum Transfer energy & transmit information Be Reflected Be Refracted Travel through a vacuum as a transverse wave

Test yourself activity

3

Red Radio wavesMen Micro wavesIn Infra Red wavesVans Visible Use Ultra VioletX-Ray X-RayGoggles

Gamma Ray waves

2.

3.

4

4. WAVE SPEEDSpeed, Frequency & Wavelength are all linked together using the following equation:-

Calculate the speed of a wave that has a frequency of 15Hz and a wavelength of 6 metres.

SPACE:

Our Solar System

5

SPEED = FREQUENCY x WAVELENGTH m/s Hz m

The Solar System consists of:• the Sun (a star) containing 98.8% of the mass of the Solar System • eight planets and their natural satellite moons containing about 0.2% of the mass of the Solar System. The planets are various sizes and distances from the Sun. They are found in this order as you move away from the sun.

• Mercury • Venus • Earth • Mars • Jupiter • Saturn • Uranus • NeptuneMy Very Easy Method Just Speeds Up Neptune!

Meteorites hit the Earth occasionally and rarely asteroids. The asteroid belt is found within our solar system between Mars and Jupiter. This separates the inner and outer planets. The inner planets are sometimes called ‘terrestrial’ or rocky dwarf planets. The outer planets are called gaseous giants. Some planets have many moons, but some have none. Comets visit us occasionally.

The Oort Cloud is an extended shell of icy objects that exist in the outermost reaches of the solar system. The Oort Cloud is roughly spherical, and is thought to be the origin of most of the long-period comets that have been observed.

6

7

SunspotsSunspots are dark spots which appear on the surface of the Sun. The spots are dark because they are cooler than the area of the Sun that surrounds them and they are often as big as the Earth. They often appear in pairs on either side of the equator, and usually last from 50 to 100 days. The number of sunspots on the surface of the Sun seems to vary over an 11 year cycle from almost zero up to over 100.

8

Compared to Earth, the Sun is enormous! It contains 99.86% of all of the mass of the entire Solar System. The Sun is 864,400 miles (1,391,000 kilometers) across. This is about 109 times the diameter of Earth. The Sun weighs about 333,000 times as much as Earth. It is so large that about 1,300,000 planet Earths can fit inside of it. Earth is about the size of an average sunspot!The Sun is the source of nearly all the energy we receive. The energy source is nuclear fusion. In nuclear fusion, hydrogen nuclei are joined together to make helium nuclei. This releases enormous amounts of energy.

A solar flare is an intense burst of radiation coming from the release of magnetic energy associated with sunspots. Flares are our Solar System’s largest explosive events. They are seen as bright areas on the Sun and they can last from minutes to hours. We typically see a solar flare by the light it releases at almost most every wavelength of the spectrum. Flares are also sites where particles (electrons, protons, and heavier particles) are accelerated.

Solar flares can disrupt power supplies and communication systems on Earth.

9

Our Moon is a naural satellite of the Earth.Activity: The Earth is 25,000 miles in circumference. The Moon is 250,000 miles away from Earth. Make an accurate/ scaled model using the following items: a globe of the Earth, a ball of string & an orange (representing the Moon).AsteroidsAsteroids are smaller than planets. They are believed to be rocks left over from the formation of the Solar System. Most are found in an ‘asteroid belt’ in orbit around the Sun between Mars and Jupiter. Asteroids may crash into each other which can result in a change in their orbit. The orbits of some asteroids cross the Earth’s orbit.Comets Comets are balls of ice and dust in orbit around the Sun. Unlike the planets which have circular orbits, the orbits of comets are elliptical. A comet’s orbit takes it very close to the Sun and then far away again. The time to complete an orbit varies - some comets take a few years, while others take millions of years to complete an orbit.

GALAXIESThese can be recognised by their swirly shape. Galaxies containg millions of stars. There are billions of galaxies in our Universe.

THE UNIVERSEThe universe is massive and is continuing to expand. Our minds cannot fathom the enormous scope and size of the universe. The size for some of the objects in the

10

The name of our galaxy is The Mily Way.

universe is so large that they are measured in light years. A light year is the distance light will travel in one year.The table below compares the size of different objects in the universe:

Task:Copy and complete the paragraph below. Use only the words in the box below to fill in the blanks.

The solar system is made of one star called ____ ___________. Orbiting around the sun are eight ________ and one __________ __________. The first four planets are called Mercury, Venus, _________ and ________. Together they are called the __________ __________. The next four are called the ________ ________, called Jupiter, ________, Uranus and ___________. The inner and outer planets are separated by an __________ belt. The final planet is a dwarf planet called _________. Some of the planets have _________. Earth has one, called the __________, while Saturn has 60!

11

Saturn asteroid Earth Neptune Moon inner planets outer planets dwarf planet planets Pluto moons Mars the Sun

Task:12

The Electromagnetic spectrum and spaceImages from the universe How can we learn about our universe if we cannot travel beyond our own solar system? The answer to this question is that we look carefully at the messages sent to us from the universe.Stars emit electromagnetic radiation. That electromagnetic radiation gives us a lot of information about a star. By using telescopes sensitive to different wavelength ranges of the spectrum, astronomers can see into a wide variety of objects in the universe. We can only see the visible region of the electromagnetic spectrum with our eyes. To help us understand information from other regions of the electromagnetic spectrum, astronomers often convert the information into a false colour image.Here are some examples:

13

Radio wavesIf we were to look at the sky with a radio telescope, the sky would appear very different from what we see in visible light. Instead of seeing point-like stars, we would see objects such as:

14

UltravioletThe ultraviolet universe appears quite different from that which is seen with visible light. Most stars are relatively cool objects which emit most of their electromagnetic radiation in the visible or near-infrared part of the spectrum. These stars disappear from view when we use an ultraviolet telescope. Ultraviolet telescopes pick out the more energetic

Infrared imagesAll objects above absolute zero emit infrared radiation. The Earth, the Sun, stars and galaxies also emit infrared radiation. More than half of the Sun’s power output is in the form of infrared light.

MicrowavesScientists discovered that there are microwaves coming from every direction in space. This is called the cosmic microwave background radiation (CMBR). CBMR is considered to be evidence for the Big Bang theory (see the end of this section for the Big Bang theory).

Visible light All stars emit at least some light in the visible region of the spectrum. Stars appear to be white at first glance, but closer observation shows a range of colours: blue, white, red, and even gold. The variation in colour is a direct consequence of their surface temperature. Cool stars radiate most of their energy in the red and infrared region of the electromagnetic spectrum and thus appear red, while hot stars emit mostly at blue and ultra-violet wavelengths, making them appear blue or white.

15

X-rayMany things in space emit X-rays; among them are black holes, neutron stars, binary star systems, supernova remnants, stars, the Sun, and even some comets. Many things in deep space give off X-rays, for example, a star orbiting a black hole. Material is pulled off the normal star into the black hole. As it does so it is heated up to very high temperatures and as a result gives off X-rays.

UltravioletThe ultraviolet universe appears quite different from that which is seen with visible light. Most stars are relatively cool objects which emit most of their electromagnetic radiation in the visible or near-infrared part of the spectrum. These stars disappear from view when we use an ultraviolet telescope. Ultraviolet telescopes pick out the more energetic

Space based and Earth based telescopes Optical telescopes on the ground can only be used at night and they cannot be used if the weather is poor or cloudy. Visible telescopes in space give much clearer images which are not affected by an atmosphere.Radio telescopes can be used in bad weather because the radio waves are not blocked by clouds as they pass through the atmosphere. Radio telescopes can also be used in the daytime as well as at night.UV and X-rays are partly blocked by the Earth’s atmosphere and so need to be placed at high altitudes or placed into orbit around the Earth.

Test yourself activity:

Absorption spectraHow can we know what is in the Sun or a star? How can we know what elements are present in the Sun or a star? Once more it is by looking at the light coming from the Sun (or star). If you examine light from the Sun (or any star) you will find that there are black lines in the spectrum. These black lines are caused by elements in the cooler outer part of the Sun absorbing light coming from inside the Sun. This pattern of black lines is known as the absorption spectrum.

16

Each element has its own unique pattern of absorption lines; these lines form a fingerprint for each element. The image below shows the absorption spectrum for the element helium. Helium will always cause the same pattern of lines. We can use this pattern to identify the presence of helium in the Sun (or in any other star).

By looking at the absorption spectra of the Sun we know that the Sun is composed of about 72% hydrogen26% helium. There are also trace amounts of other elements such as oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.

Tip: You do not need to remember the composition of the Sun. You just need to know that the absorption spectrum of the Sun tells us what elements are present.

Distance and the universe

17

It is extremely difficult for us to take in the size of the universe. The distances are huge!The Sun is 150 million kilometres from the Earth, but that’s a tiny distance compared with the distance to other stars, or other galaxies. We use a larger unit of measurement for these distances known as the light year.

A light-year: is the distance light travels in a year.To give you a ‘feel’ for the distances involved, think about the following information. Light takes about:• eight minutes to reach us from the Sun • five hours to reach Pluto from the Sun • four years to reach us from the next nearest star, Proxima Centauri • 100000 years to cross the Milky Way galaxy To put the distance in light years, we say, ‘the nearest star is four light years away; the furthest galaxies are 13000 million light years away’.

Measuring distances to other stars and to very distant galaxies is not easy, so the data is uncertain.

Task:

18

19

20