Whitley Academy Science Faculty

1. Whitley AcademyScience Faculty Year 10 into Year 11 Summer Homework

2. What to do ….. Use this booklet to create flash cards on the topics below to help you in your lessons in September, and help you relearn some of the most difficult areas from the end of year exam. Please ensure you don’t create cards for parts in the book that are ‘biology only’/’physics only’/’chemistry only’ unless you have chosen triple science as an option. Also, do not create cards for parts labelled ‘HT’ if you know you will be doing foundation tier. Create cards for HT if you are aiming for higher tier (grades 5 to 9). • Waves • Magnification and microscopy. • Series and Parallel. • Periodic table.

3. LearnIT! • KnowIT! • Waves in air, fluids and solids • Transverse and longitudinal waves • Properties of waves • Reflection of waves (physics only) • Sound waves (physics only) (HT) • Waves for detection and exploration (physics only) (HT)

4. Transverse Wave In a transversewave the particles within the wave move perpendicular (at 90o) to the direction the wave is travelling. This is the wave produced in a rope when it is flicked up and down. Examples of transverse waves are: Water waves, electromagnetic (light) waves and guitar strings. Longitudinal waves are compression (squash) waves where the particles are vibrating in the same direction as the wave movement. This is the wave produced when a spring is squashed and released. Examples of longitudinal waves are: Sound waves and a type of seismic (P) wave. Transverse and Longitudinal Waves Longitudinal Wave Remember, the particles in a wave move up and down or backwards and forwards only. It is energy, NOT the particles, that move from one place to another!

5. Wavelength (m) – the distance from one point on a wave to the same point on the next wave. Amplitude (m) – the waves maximum displacement of a point on a wave from its undisturbed position. Frequency (Hz) – the number of waves passing a point per second. Period (s) -the time taken to produce one complete wave. The displacement of a transverse wave is described as peaks and troughs. In a longitudinal wave these are described as compressions and rarefactions. Transverse and Longitudinal Waves

6. Wave speed and wave period calculations Properties of waves Wave speed is the speed at which energy is transferred by the wave (or how quickly the wave moves) through the medium it is travelling in. Wave speed (m/s) = Frequency (Hz) x Wavelength (m) v = f λ Wave period (T) is the time it takes one complete wave to pass a point (in seconds). Period (s) = 1 / Frequency (Hz) T = 1/f The wave opposite has a frequency of 0.5Hz and a wavelength of 6cm (0.06m). Calculate the wave period and the wave speed. Wave period = 1/f T = 1/0.5 = 2s Wave speed = f x λ v = 0.5 x 0.06 = 0.03m/s

7. Method for measuring the speed of sound waves in air Properties of waves 100m The cannon fires and the stopwatch is started (you can see a flash of light which takes almost zero time to travel 100m). When the sound reaches the observer the stopwatch is stopped. The time was 0.3s This will give the time for sound to travel 100m. Speed (m/s) = Distance (m) / Time (s) Speed of sound = 100 / 0.3 = 333.3m/s In the laboratory, a sound from a loudspeaker passes two microphones a set distance apart. The time recorded for the sound to travel this distance is measured and speed is calculated using the same formula as above.

8. Method for measuring the speed of ripples on a water surface Properties of waves A ripple tank is used to make waves which are seen under the glass tank. A strobe light has its frequency of flashes adjusted until the wave appears stationary – this is the frequency of the water wave. Then, the wavelength of the water wave is measured by using a ruler to measure the distance from one peak to the next peak (white line to white line). This is converted to metres. Wave speed (m/s) = Frequency (Hz) x Wavelength (m) If the frequency of the water wave is 5Hz and the wavelength is 0.6cm: wave speed = 0.5 x 0.006 = 0.03m/s Strobe

9. When a sound wave travels from one medium to another e.g. air to water, the frequency remains the same. This is because frequency is a property of the object producing the sound, not the medium it travels through. Sound waves changing medium (physics only) Air Water The sound wave will travel faster in water than air. Remember, Wave speed (m/s) = Frequency (Hz) x Wavelength (m) or f = v / λ. So, if the frequency remains the same, as velocity increases, the wavelength must also increase proportionally. If a sound wave has a frequency of 260Hz: Speed of sound in air = 330m/s. Speed of sound in water = 1500m/s. λ in air = 330 / 260 = 1.27m λ in water = 1500 / 260 = 5.77m

10. When light waves strike a boundary they can be reflected, absorbed or transmitted depending on the substance they strike. Reflection of waves (physics only) Reflected light bounces off the object surface Transmitted light passes through the object Absorbed light heats the object Light reflected from a specular surface, e.g. a mirror, reflects at the same angle it strikes the mirror. Angle of incidence (i) = angle of reflection (r)

11. Sound waves can travel through solids causing vibrations in the solid. In the ear, sound waves cause the ear drum and other parts to vibrate which causes the sensation of sound. The conversion of sound waves to solids only happens over a limited frequency range. This restricts the human hearing range to between 20Hz and 20,000Hz (20kHz). Sound waves (physics only) (HT) Eardrum Sound waves

12. Ultrasound waves used for detection Ultrasounds are sound waves with a higher frequency than humans can hear. Waves for detection (physics only) (HT) Ultrasound waves are partially reflected when they meet a boundary between two different media. The time taken for the reflections to meet a detector can be used to determine how far away the boundary is. Ultrasound waves can therefore be used for medical imaging. A similar technique, using higher frequencies, can be used in industry to detect flaws and cracks inside castings. This could prevent a potentially dangerous casting being used, for example, in an aircraft engine.

13. Earthquake epicentre Seismic waves used for exploration Waves for exploration (physics only) (HT) Earthquakes produce P and S waves. This information can be used to determine the size, density and state of the Earth’s structure. As S waves do not penetrate the outer core, they can not be used to determine whether the inner core is liquid or solid. P waves: fast longitudinal; travel at different speeds through solids and liquids. S waves: slower transverse; cannot travel through liquids. The study of seismic waves provided new evidence that led to discoveries about parts of the Earth which are not directly observable.

14. Echo sounding Waves for exploration (physics only) (HT) Echo location or SONAR uses high frequency sound waves to detect objects in deep water (shipwrecks, shoals of fish) and measure water depth. Ultrasound waves travel at 1500m/s in sea water. The transmitter sends out a wave which is received 4.6s later. The depth of water under the ship can be calculated as: Distance (m) = speed (m/s) x time (s) so: distance = 1500 x 4.6 = 6900m Remember, this is the time to go to the bottom and back. Therefore depth = 6900 /2 = 3450m

15. Cell structure - Microscopy light microscope First ones used in 1590’s electron microscope First ones used in 1960’s Resolution: The shortestdistance between two objects that can be seen clearly. Video - Types of microscopes

16. Electron microscopeshave a higher magnification and resolution than light microscopes. This means that scientists can see more sub- cellular structures (structures within the cells). Cell structure - Microscopy nucleus mitochondria mitochondrion Light microscopes image can let us see structures like nuclei and mitochondria. Electron microscopes image can let us see the internal structures of a chloroplast and mitochondrion.

17. You can calculatethe magnification of an image by using the equation: Cell structure - Microscopy MAGNIFICATION: the number of times bigger the image looks compared to the object IMAGE: what is viewed through the microscope lenses OBJECT: the ACTUAL specimen under the microscope magnification M = size of image I real size of the object A WORKED EXAMPLE 1: A magnified animal cell structure has a diameter of 6 mm. The actual diameter of the structure is 0.15mm. Calculate how many times the structure has been magnified. IMAGE M = I OBJECT A M = 6 M = 40 You may need to to write your answers in standard form. 0.15 You may need to be able rearrange to change the subject of the equation.

18. Cell structure - Microscopy WORKED EXAMPLE 2: The actual length of a cell structure is 30𝛍m. It is magnified 40 times. Calculate the length of the magnified cell structure in mm. Rearrange the equation to make I the subject magnification M = size of image I OBJECT (A) OBJECT (A) real size of the object A MAGNIFICATION (M) You may need to to write your answers in standard form. x A A x M = I Multiply both sides by A A Cancel out the As To convert to mm you need to divide by 1000 Put I on the left of the equation I = M x A I = 1200𝛍m I = 40 x 30 I = 1.2mm

19. Making a wet mount slide e.g. onion cells • Place a thin section of the specimen onto slide. • Place a drop of water in the middle of the slide or stain the specimen. • Gently lower cover slip onto the specimen without trapping air bubbles. • Soak up any excess liquid with a paper towel. • Switch on the light source and place your slide on the stage. • Use the lowest objective lens and turn the focusing wheel to move the lens close to the slide. • Slowly adjust the focusing wheel until you can see a clear image. • Increase the magnification by changing the objective lens and re-focus. Cell structure – Microscopy • Drawing what you see • Clear line drawing – no shading • Label main cell structures • Add a title and the magnification. See GCSE Practical Guide - Biology – Microscopy on Huddle - Microscopy Practical guide

20. Effectiveness of disinfectants and antibiotics on bacteria experiment • Agar inoculated with BACTERIA. • Paper discs containing antiseptics and antibiotics placed on bacteria and left to grow. • Water disc used as a CONTROL. • If bacteria don’t grow around the disc then the chemical is effective at killing bacteria. • Area where bacteria don’t grow is called ZONE OF INHIBITION. • See GCSE Practical Guide - Practical guide - Microbiology Bacteria multiply by binary fission (a cell division where two identical cells are formed). In the right conditions cells can divide as often as every 20 minutes. Cell structure - Culturing microorganisms (biology only) Bacteria can be grown in the lab • A culture medium (agar) usedcontaining an energy source (carbohydrate) and minerals. • Petri dishes and agar must be sterilised before use to kill microorganisms. • Inoculating loops used to transfer bacteria after being heated in a Bunsen flame. • The lid of the Petri dish should be sealed with tape to stop other microorganisms getting in (must not be fully sealed so oxygen can get in) • In school, Petri dishes are incubated at 25°C to reduce risk of growth of pathogens that might be harmful to humans. Bacteria lines

21. Series and Parallel Circuits Series Circuits • Series circuits consist of one loop of wire. • For components connected in series: • there is the same current through each component • the total potential difference of the power supply is shared between the components • the total resistance of two components is the sum of the resistance of each component. • Rtotal = R1 + R2 • resistance, R, in ohms, Ω

22. Series and Parallel Circuits Parallel Circuits • Parallel Circuits consist of two or more loops (branches) of wire. • For components connected in parallel: • the potential difference across each component is the same • the total current through the whole circuit is the sum of the currents through the separate components on each loop (branch) • the total resistance of tworesistors is less than the resistance of the smallest individual resistor.

23. The elements are arranged in order of increasing atomic number. Periodic table Elements with similar properties are in columns, known as groups. Elements in the same group have the same number of electrons in their outer shell. It is called a periodic table because similar properties occur at regular intervals The rows in the table are called periods Group = electrons in outer shell Period = number of shells Group = 7 Period = 3

24. 1864 John Newlands published the law of octaves. However the table was incomplete and elements were placed in inappropriate groups 1808 John Dalton published a table of elements that were arranged in order of their atomic weights, which had been measured in various chemical reactions Periodic table 1869 Dmitri Mendeleev overcame Dalton’s problem by leaving gaps for the elements that he thought had not been discovered and in some places changed the order based on atomic weight (e.g. Argon and Potassium). Elements with properties predicted by Mendeleev were eventually discovered. Early20th Century - Scientists began to find out more about the atom and knowledge of isotopes explained why the order was not always correct.

25. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ? The elements can be divided into metals and non-metals. Periodic table Elements that do not form positive ions are non-metals Elements that tend to form positive ions are metals 2 1 3 0 4 5 6 7 Non metals – found towards the right and towards the top of the periodic table Most elements are metals – found towards the left and towards the bottom of the periodic table