Physics Past Paper PDF

1 Motion, forces and energy 1.1 Physical quantities and measurement techniques 1 Describe how to measure a variety of lengths with appropriate precision using tapes, rulers and micrometers (including reading the scale on an analogue micrometer) 2 Describe how to use a measuring cylinder to measu...

1 Motion, forces and energy 1.1 Physical quantities and measurement techniques 1 Describe how to measure a variety of lengths with appropriate precision using tapes, rulers and micrometers (including reading the scale on an analogue micrometer) 2 Describe how to use a measuring cylinder to measure the volume of a liquid and to determine the volume of a solid by displacement 3 Describe how to measure a variety of time intervals using clocks and digital timers 4 Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum) 5 Understand that a scalar quantity has magnitude (size) only and that a vector quantity has magnitude and direction 6 Know that the following quantities are scalars: distance, speed, time, mass, energy and temperature 7 Know that the following quantities are vectors: displacement, force, weight, velocity, acceleration, momentum, electric field strength and gravitational field strength 8 Determine, by calculation or graphically, the resultant of two vectors at right angles1.2 Motion 1 Define speed as distance travelled per unit time and define velocity as change in displacement per unit time 2 Recall and use the equation speed = distance time v = s t 3 Recall and use the equation average speed = total distance travelled total time taken 4 Define acceleration as change in velocity per unit time; recall and use the equation acceleration = change in velocity time taken a = ∆v ∆t 5 State what is meant by, and describe examples of, uniform acceleration and non-uniform acceleration 6 Know that a deceleration is a negative acceleration and use this in calculations 7 Sketch, plot and interpret distance--time and speed--time graphs 8 Determine from the shape of a distance--time graph when an object is: \(a) at rest \(b) moving with constant speed \(c) accelerating \(d) decelerating 9 Determine from the shape of a speed--time graph when an object is: \(a) at rest \(b) moving with constant speed \(c) moving with constant acceleration \(d) moving with changing acceleration 10 State that the acceleration of free fall g for an object near to the surface of the Earth is approximately constant and is approximately 9.8m/s 2 11 Calculate speed from the gradient of a distance--time graph 12 Calculate the area under a speed--time graph to determine the distance travelled for motion with constant speed or constant acceleration 13 Calculate acceleration from the gradient of a speed--time graph1.3 Mass and weight 1 State that mass is a measure of the quantity of matter in an object at rest relative to the observer 2 State that the mass of an object resists change from its state of rest or motion (inertia) 3 Know that weights, and therefore masses, may be compared using a beam balance or equal-arm balance 4 Describe how to determine mass using an electronic balance 5 Describe how to measure weight using a force meter 6 Define gravitational field strength as force per unit mass; recall and use the equation gravitational field strength = weight mass g = W m and know that this is equivalent to the acceleration of free fall 7 State that a gravitational field is a region in which a mass experiences a force due to gravitational attraction 1.4 Density 1 Define density as mass per unit volume; recall and use the equation density = mass volume ρ = m V 2 Describe how to determine the density of a liquid, of a regularly shaped solid and of an irregularly shaped solid which sinks in a liquid (volume by displacement), including appropriate calculations 1.5 Forces 1.5.1 Balanced and unbalanced forces 1 Identify and use different types of force, including weight (gravitational force), friction, drag, air resistance, tension (elastic force), electrostatic force, magnetic force, thrust (driving force) and contact force 2 Identify forces acting on an object and draw free-body diagram(s) representing the forces 3 State Newton's first law as 'an object either remains at rest or continues to move in a straight line at constant speed unless acted on by a resultant force' 4 State that a force may change the velocity of an object by changing its direction of motion or its speed 5 Determine the resultant of two or more forces acting along the same straight line 6 Recall and use the equation resultant force = mass × acceleration F = ma 7 State Newton's third law as 'when object A exerts a force on object B, then object B exerts an equal and opposite force on object A' 8 Know that Newton's third law describes pairs of forces of the same type acting on different objects1.5 Forces continued 1.5.2 Friction 1 Describe friction as a force that may impede motion and produce heating 2 Understand the motion of objects acted on by a constant weight or driving force, with and without drag (including air resistance or resistance in a liquid) 3 Explain how an object reaches terminal velocity 4 Define the thinking distance, braking distance and stopping distance of a moving vehicle 5 Explain the factors that affect thinking and braking distance including speed, tiredness, alcohol, drugs, load, tyre surface and road conditions 1.5.3 Elastic deformation 1 Know that forces may produce a change in size and shape of an object 2 Define the spring constant as force per unit extension; recall and use the equation spring constant = force extension k = F x 3 Sketch, plot and interpret load--extension graphs for an elastic solid and describe the associated experimental procedures 4 Define and use the term 'limit of proportionality' for a load--extension graph and identify this point on the graph (an understanding of the elastic limit is not required) 1.5.4 Circular motion 1 Describe, qualitatively, motion in a circular path due to a force perpendicular to the motion as: \(a) speed increases if force increases, with mass and radius constant \(b) radius decreases if force increases, with mass and speed constant \(c) an increased mass requires an increased force to keep speed and radius constant ( F = mv2 r is not required) 1.5.5 Turning effect of forces 1 Describe the moment of a force as a measure of its turning effect and give everyday examples 2 Define the moment of a force as moment = force × perpendicular distance from the pivot; recall and use this equation 3 State and use the principle of moments for an object in equilibrium 4 Describe an experiment to verify the principle of moments 1.5.6 Centre of gravity 1 State what is meant by centre of gravity 2 Describe how to determine the position of the centre of gravity of a plane lamina using a plumb line 3 Describe, qualitatively, the effect of the position of the centre of gravity on the stability of simple objects1.6 Momentum 1 Define momentum as mass × velocity; recall and use the equation p = mv 2 Define impulse as force × time for which force acts; recall and use the equation impulse = FΔt = Δ(mv) 3 Apply the principle of the conservation of momentum to solve simple problems in one dimension 4 Define resultant force as the change in momentum per unit time; recall and use the equation resultant force = change in momentum time taken F = ∆p ∆t 1.7 Energy, work and power 1.7.1 Energy 1 State that energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal) 2 Describe how energy is transferred between stores during events and processes, including examples of transfer by forces (mechanical work done), electrical currents (electrical work done), heating, and by electromagnetic, sound and other waves 3 Know the principle of the conservation of energy and apply this principle to the transfer of energy between stores during events and processes 4 Recall and use the equation for kinetic energy Ek = 1/2mv2 5 Recall and use the equation for the change in gravitational potential energy ΔE p = mgΔh 1.7.2 Work 1 Recall and use the equation work done = force × distance moved in the direction of the force W = Fd1.7 Energy, work and power continued 1.7.3 Energy resources 1 List renewable and non-renewable energy sources 2 Describe how useful energy may be obtained, or electrical power generated, from: \(a) chemical energy stored in fossil fuels \(b) chemical energy stored in biofuels \(c) hydroelectric resources \(d) solar radiation \(e) nuclear fuel \(f) geothermal resources \(g) wind \(h) tides \(i) waves in the sea including references to a boiler, turbine and generator where they are used 3 Describe advantages and disadvantages of each method limited to whether it is renewable, when and whether it is available, and its impact on the environment 1.7.4 Efficiency 1 Define efficiency as: \(a) (%) efficiency = (useful energy output) (total energy input) ( × 100%) \(b) (%) efficiency = (useful power output) (total power input) ( × 100%) and recall and use these equations 1.7.5 Power 1 Define power as work done per unit time and also as energy transferred per unit time; recall and use the equations \(a) power = work done time taken P = W t \(b) power = energy transferred time taken P = ∆E t1.8 Pressure 1 Define pressure as force per unit area; recall and use the equation pressure = force area p = F A 2 Describe how pressure varies with force and area in the context of everyday examples 3 State that the pressure at a surface produces a force in a direction at right angles to the surface and describe an experiment to show this 4 Describe how the height of a liquid column in a liquid barometer may be used to determine the atmospheric pressure 5 Describe, quantitatively, how the pressure beneath the surface of a liquid changes with depth and density of the liquid 6 Recall and use the equation for the change in pressure beneath the surface of a liquid change in pressure = density × gravitational field strength × change in height ∆p = ρg∆h2 Thermal physics 2.1 Kinetic particle model of matter 2.1.1 States of matter 1 Know the distinguishing properties of solids, liquids and gases 2 Know the terms for the changes in state between solids, liquids and gases (gas to solid and solid to gas transfers are not required) 2.1.2 Particle model 1 Describe, qualitatively, the particle structure of solids, liquids and gases, relating their properties to the forces and distances between particles and to the motion of the particles (atoms, molecules, ions and electrons) 2 Describe the relationship between the motion of particles and temperature, including the idea that there is a lowest possible temperature (−273°C), known as absolute zero, where the particles have least kinetic energy 3 Describe the pressure and the changes in pressure of a gas in terms of the forces exerted by particles colliding with surfaces, creating a force per unit area 4 Explain qualitatively, in terms of particles, the relationship between: \(a) pressure and temperature at constant volume \(b) volume and temperature at constant pressure \(c) pressure and volume at constant temperature 5 Recall and use the equation p1 V1 = p2V2, including a graphical representation of the relationship between pressure and volume for a gas at constant temperatur2.2 Thermal properties and temperatuare 2.2.1 Thermal expansion of solids, liquids and gases 1 Explain applications and consequences of thermal expansion in the context of common examples, including the liquid-in-glass thermometer 2 Explain, in terms of the motion and arrangement of particles, the thermal expansion of solids, liquids and gases, and state the relative order of magnitudes of the expansion of solids, liquids and gases 3 Convert temperatures between kelvin and degrees Celsius; recall and use the equation T (in K) = θ (in °C) + 273 2.2.2 Specific heat capacity 1 Know that an increase in the temperature of an object increases its internal energy 2 Describe an increase in temperature of an object in terms of an increase in the average kinetic energies of all of the particles in the object 3 Define specific heat capacity as the energy required per unit mass per unit temperature increase; recall and use the equation specific heat capacity = change in energy mass × change in temperature c = ∆E m∆θ 4 Describe experiments to measure the specific heat capacity of a solid and of a liquid 2.2.3 Melting, boiling and evaporation 1 Describe melting, solidification, boiling and condensation in terms of energy transfer without a change in temperature 2 Know the melting and boiling temperatures for water at standard atmospheric pressure 3 Describe the differences between boiling and evaporation 4 Describe evaporation in terms of the escape of more energetic particles from the surface of a liquid 5 Describe how temperature, surface area and air movement over a surface affect evaporation 6 Explain how evaporation causes cooling 7 Describe latent heat as the energy required to change the state of a substance and explain it in terms of particle behaviour and the forces between particles2.3 Transfer of thermal energy 2.3.1 Conduction 1 Describe experiments to distinguish between good and bad thermal conductors 2 Describe thermal conduction in all solids in terms of atomic or molecular lattice vibrations and also in terms of the movement of free (delocalised) electrons in metallic conductors 2.3.2 Convection 1 Explain convection in liquids and gases in terms of density changes and describe experiments to illustrate convection 2.3.3 Radiation 1 Describe the process of thermal energy transfer by infrared radiation and know that it does not require a medium 2 Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of infrared radiation 3 Describe how the rate of emission of radiation depends on the surface temperature and surface area of an object 4 Describe experiments to distinguish between good and bad emitters of infrared radiation 5 Describe experiments to distinguish between good and bad absorbers of infrared radiation 2.3.4 Consequences of thermal energy transfer 1 Explain everyday applications using ideas about conduction, convection and radiation, including: \(a) heating objects such as kitchen pans \(b) heating a room by convection \(c) measuring temperature using an infrared thermometer \(d) using thermal insulation to maintain the temperature of a liquid and to reduce thermal energy transfer in buildings 3 Waves 3.1 General properties of waves 1 Know that waves transfer energy without transferring matter 2 Describe what is meant by wave motion as illustrated by vibrations in ropes and springs and by experiments using water waves 3 Describe the features of a wave in terms of wavefront, wavelength, frequency, crest (peak), trough, amplitude and wave speed 4 Define the terms: \(a) frequency as the number of wavelengths that pass a point per unit time \(b) wavelength as the distance between two consecutive, identical points such as two consecutive crests \(c) amplitude as the maximum distance from the mean position3.1 General properties of waves continued 5 Recall and use the equation wave speed = frequency × wavelength v = f λ 6 Know that for a transverse wave, the direction of vibration is at right angles to the direction of the energy transfer, and give examples such as electromagnetic radiation, waves on the surface of water, and seismic S-waves (secondary) 7 Know that for a longitudinal wave, the direction of vibration is parallel to the direction of the energy transfer, and give examples such as sound waves and seismic P-waves (primary) 8 Describe how waves can undergo: \(a) reflection at a plane surface \(b) refraction due to a change of speed \(c) diffraction through a gap 9 Describe how wavelength and gap size affects diffraction through a gap 10 Describe the use of a ripple tank to show: \(a) reflection at a plane surface \(b) refraction due to a change in speed caused by a change in depth \(c) diffraction due to a gap \(d) diffraction due to an edge 11 Describe how wavelength affects diffraction at an edge 3.2 Light 3.2.1 Reflection of light 1 Define and use the terms normal, angle of incidence and angle of reflection 2 Describe an experiment to illustrate the law of reflection 3 Describe an experiment to find the position and characteristics of an optical image formed by a plane mirror (same size, same distance from mirror as object and virtual) 4 State that for reflection, the angle of incidence is equal to the angle of reflection and use this in constructions, measurements and calculations 3.2.2 Refraction of light 1 Define and use the terms normal, angle of incidence and angle of refraction 2 Define refractive index n as n = sin i sin r ; recall and use this equation 3 Describe an experiment to show refraction of light by transparent blocks of different shapes 4 Define the terms critical angle and total internal reflection; recall and use the equation n = 1 sin c 5 Describe experiments to show internal reflection and total internal reflection 6 Describe the use of optical fibres, particularly in telecommunications, stating the advantages of their use in each cont3.2 Light continued 3.2.3 Thin lenses 1 Describe the action of thin converging and thin diverging lenses on a parallel beam of light 2 Define and use the terms focal length, principal axis and principal focus (focal point) 3 Draw ray diagrams to illustrate the formation of real and virtual images of an object by a converging lens and know that a real image is formed by converging rays and a virtual image is formed by diverging rays 4 Define linear magnification as the ratio of image length to object length; recall and use the equation linear magnification = image length object length 5 Describe the use of a single lens as a magnifying glass 6 Draw ray diagrams to show the formation of images in the normal eye, a short-sighted eye and a long-sighted eye 7 Describe the use of converging and diverging lenses to correct long-sightedness and short-sightedness 3.2.4 Dispersion of light 1 Describe the dispersion of light as illustrated by the refraction of white light by a glass prism 2 Know the traditional seven colours of the visible spectrum in order of frequency and in order of wavelength 3.3 Electromagnetic spectrum 1 Know the main regions of the electromagnetic spectrum in order of frequency and in order of wavelength 2 Know that the speed of all electromagnetic waves in: \(a) a vacuum is 3.0 × 108m/s \(b) air is approximately the same as in a vacuum 3 Describe the role of the following components in the stated applications: \(a) radio waves -- radio and television communications, astronomy \(b) microwaves -- satellite television, mobile (cell) phone, Bluetooth, microwave ovens \(c) infrared -- household electrical appliances, remote controllers, intruder alarms, thermal imaging, optical fibres \(d) visible light -- photography, vision \(e) ultraviolet -- security marking, detecting counterfeit bank notes, sterilising water \(f) X-rays -- hospital use in medical imaging, security scanners, killing cancerous cells, engineering applications such as detecting cracks in metal \(g) gamma rays -- medical treatment in detecting and killing cancerous cells, sterilising food and medical equipment, engineering applications such as detecting cracks in metal 4 Describe the damage caused by electromagnetic radiation, including: \(a) excessive exposure causing heating of soft tissues and burns \(b) ionising effects caused by ultraviolet (skin cancer and cataracts), X-rays and gamma rays (cell mutation and cancer)3.4 Sound 1 Describe the production of sound by vibrating sources 2 Describe the longitudinal nature of sound waves and describe compressions and rarefactions 3 State the approximate range of frequencies audible to humans as 20Hz to 20000Hz 4 Explain why sound waves cannot travel in a vacuum and describe an experiment to demonstrate this 5 Describe how changes in amplitude and frequency affect the loudness and pitch of sound waves 6 Describe how different sound sources produce sound waves with different qualities (timbres), as shown by the shape of the traces on an oscilloscope 7 Describe an echo as the reflection of sound waves 8 Describe simple experiments to show the reflection of sound waves 9 Describe a method involving a measurement of distance and time for determining the speed of sound in air 10 Know that the speed of sound in air is approximately 330--350m/s 11 Know that, in general, sound travels faster in solids than in liquids and faster in liquids than in gases 12 Define ultrasound as sound with a frequency higher than 20kHz 13 Describe the uses of ultrasound in cleaning, prenatal and other medical scanning, and in sonar (including calculation of depth or distance from time and wave speed) 4 Electricity and magnetism 4.1 Simple magnetism and magnetic fields 1 Describe the forces between magnetic poles and between magnets and magnetic materials, including the use of the terms north pole (N pole), south pole (S pole), attraction and repulsion, magnetised and unmagnetised 2 Describe induced magnetism 3 State the difference between magnetic and non-magnetic materials 4 State the differences between the properties of temporary magnets (made of soft iron) and the properties of permanent magnets (made of steel) 5 Describe a magnetic field as a region in which a magnetic pole experiences a force 6 Describe the plotting of magnetic field lines with a compass or iron filings and the use of a compass to determine the direction of the magnetic field 7 Draw the pattern and direction of the magnetic field lines around a bar magnet 8 State that the direction of the magnetic field at a point is the direction of the force on the N pole of a magnet at that point 9 Know that the relative strength of a magnetic field is represented by the spacing of the magnetic field lines 10 Describe uses of permanent magnets and electromagnets4.2 Electrical quantities continued 4.2.3 Electromotive force and potential difference continued 2 Define p.d. (potential difference) as the work done by a unit charge passing through a component; recall and use the equation p.d. = work done (on a component) charge V = W Q 3 Know that e.m.f. and p.d. are measured in volts and that the volt is given by joule per coulomb (J/C) 4 Describe the use of voltmeters (analogue and digital) with different ranges 5 Calculate the total e.m.f. where several sources are arranged in series 6 State that the e.m.f of identical sources connected in parallel is equal to the e.m.f. of one of the sources 4.2.4 Resistance 1 Recall and use the equation resistance = p.d. current R = V I 2 Describe an experiment to determine resistance using a voltmeter and an ammeter and do the appropriate calculations 3 Recall and use, for a wire, the direct proportionality between resistance and length, and the inverse proportionality between resistance and cross-sectional area 4 State Ohm's law, including reference to constant temperature 5 Sketch and explain the current--voltage graphs for a resistor of constant resistance, a filament lamp and a diode 6 Describe the effect of temperature increase on the resistance of a resistor, such as the filament in a filament lamp 4.3 Electric circuits 4.3.1 Circuit diagrams and circuit components 1 Draw and interpret circuit diagrams with cells, batteries, power supplies, generators, oscilloscopes, potential dividers, switches, resistors (fixed and variable), heaters, thermistors (NTC only), light-dependent resistors (LDRs), lamps, motors, ammeters, voltmeters, magnetising coils, transformers, fuses, relays, diodes and light-emitting diodes (LEDs), and know how these components behave in the circuit4.3 Electric circuits continued 4.3.2 Series and parallel circuits 1 Recall and use in calculations, the fact that: \(a) the current at every point in a series circuit is the same \(b) the sum of the currents entering a junction in a parallel circuit is equal to the sum of the currents that leave the junction \(c) the total p.d. across the components in a series circuit is equal to the sum of the individual p.d.s across each component \(d) the p.d. across an arrangement of parallel resistances is the same as the p.d. across one branch in the arrangement of the parallel resistances 2 Calculate the combined resistance of two or more resistors in series 3 Calculate the combined resistance of two resistors in parallel 4 Calculate current, voltage and resistance in parts of a circuit or in the whole circuit 4.3.3 Action and use of circuit components 1 Describe the action of negative temperature coefficient (NTC) thermistors and light-dependent resistors and explain their use as input sensors 2 Describe the action of a variable potential divider 3 Recall and use the equation for two resistors used as a potential divider R1 R2 = V1 V2 4.4 Practical electricity 4.4.1 Uses of electricity 1 State common uses of electricity, including heating, lighting, battery charging and powering motors and electronic systems 2 State the advantages of connecting lamps in parallel in a lighting circuit 3 Recall and use the equation power = current × voltage P = IV 4 Recall and use the equation energy = current × voltage × time E = IVt 5 Define the kilowatt-hour (kWh) and calculate the cost of using electrical appliances where the energy unit is the k4.4 Practical electricity continued 4.4.2 Electrical safety 1 State the hazards of: \(a) damaged insulation \(b) overheating cables \(c) damp conditions \(d) excess current from overloading of plugs, extension leads, single and multiple sockets when using a mains supply 2 Explain the use and operation of trip switches and fuses and choose appropriate fuse ratings and trip switch settings 3 Explain what happens when a live wire touches a metal case that is earthed 4 Explain why the outer casing of an electrical appliance must be either non-conducting (double-insulated) or earthed 5 Know that a mains circuit consists of a live wire (line wire), a neutral wire and an earth wire and explain why a switch must be connected into the live wire for the circuit to be switched off safely 6 Explain why fuses and circuit breakers are connected into the live wire 4.5 Electromagnetic effects 4.5.1 Electromagnetic induction 1 Describe an experiment to demonstrate electromagnetic induction 2 State that the magnitude of an induced e.m.f. is affected by: \(a) the rate of change of the magnetic field or the rate of cutting of magnetic field lines \(b) the number of turns in a coil 3 State and use the fact that the effect of the current produced by an induced e.m.f. is to oppose the change producing it (Lenz's law) and describe how this law may be demonstrated 4.5.2 The a.c. generator 1 Describe a simple form of a.c. generator (rotating coil or rotating magnet) and the use of slip rings and brushes where needed 2 Sketch and interpret graphs of e.m.f. against time for simple a.c. generators and relate the position of the generator coil to the peaks, troughs and zeros of the e.m.f. 4.5.3 Magnetic effect of a current 1 Describe the pattern and direction of the magnetic field due to currents in straight wires and in solenoids and state the effect on the magnetic field of changing the magnitude and direction of the current 2 Describe how the magnetic effect of a current is used in relays and loudspeakers and give examples of their application4.5 Electromagnetic effects continued 4.5.4 Forces on a current-carrying conductor 1 Describe an experiment to show that a force acts on a current-carrying conductor in a magnetic field, including the effect of reversing: \(a) the current \(b) the direction of the field 2 Recall and use the relative directions of force, magnetic field and current 3 Describe the magnetic field patterns between currents in parallel conductors and relate these to the forces on the conductors (excluding the Earth's field) 4.5.5 The d.c. motor 1 Know that a current-carrying coil in a magnetic field may experience a turning effect and that the turning effect is increased by increasing: \(a) the number of turns on the coil \(b) the current \(c) the strength of the magnetic field 2 Describe the operation of an electric motor, including the action of a split-ring commutator and brushes 4.5.6 The transformer 1 Describe the structure and explain the principle of operation of a simple iron-cored transformer 2 Use the terms primary, secondary, step-up and step-down 3 Recall and use the equation V p Vs = N p Ns where P and S refer to primary and secondary 4 State the advantages of high-voltage transmission and explain why power losses in cables are smaller when the voltage is greater 4.6 Uses of an oscilloscope 1 Describe the use of an oscilloscope to display waveforms (the structure of an oscilloscope is not required) 2 Describe how to measure p.d. and short intervals of time with an oscilloscope using the Y-gain and timebase5 Nuclear physics 5.1 The nuclear model of the atom 5.1.1 The atom 1 Describe the structure of the atom in terms of a positively charged nucleus and negatively charged electrons in orbit around the nucleus 2 Describe how alpha-particle scattering experiments provide evidence for: \(a) a very small nucleus surrounded by mostly empty space \(b) a nucleus containing most of the mass of the atom \(c) a nucleus that is positively charged 5.1.2 The nucleus 1 Describe the composition of the nucleus in terms of protons and neutrons 2 Describe how atoms form positive ions by losing electrons or negative ions by gaining electrons 3 Define the terms proton number (atomic number) Z and nucleon number (mass number) A and be able to calculate the number of neutrons in a nucleus 4 Explain the term nuclide and use the nuclide notation A ZX 5 Explain what is meant by an isotope and state that an element may have more than one isotope 5.2 Radioactivity 5.2.1 Detection of radioactivity 1 Describe the detection of alpha particles (α-particles) using a cloud chamber or spark counter and the detection of beta particles (β-particles) (β-particles will be taken to refer to β− ) and gamma radiation (γ-radiation) by using a Geiger-Müller tube and counter 2 Use count rate measured in counts/s or counts/minute 3 Know what is meant by background radiation 4 Know the sources that make a significant contribution to background radiation including: \(a) radon gas (in the air) \(b) rocks and buildings \(c) food and drink \(d) cosmic rays 5 Use measurements of background radiation to determine a corrected count rate 5.2.2 The three types of emission 1 Describe the emission of radiation from a nucleus as spontaneous and random in direction 2 Describe α-particles as two protons and two neutrons (helium nuclei), β-particles as high-speed electrons from the nucleus and γ-radiation as high-frequency electromagnetic waves 3 State, for α-particles, β-particles and γ-radiation: \(a) their relative ionising effects \(b) their relative penetrating powers 4 Describe the deflection of α-particles, β-particles and γ-radiation in electric fields and magnetic fields5.2 Radioactivity continued 5.2.3 Radioactive decay 1 Know that radioactive decay is a change in an unstable nucleus that can result in the emission of α-particles or β-particles and/or γ-radiation and know that these changes are spontaneous and random 2 Use decay equations, using nuclide notation, to show the emission of α-particles, β-particles and γ-radiation 5.2.4 Fission and fusion 1 Describe the process of fusion as the formation of a larger nucleus by combining two smaller nuclei with the release of energy, and recognise fusion as the energy source for stars 2 Describe the process of fission when a nucleus, such as uranium-235 (U-235), absorbs a neutron and produces daughter nuclei and two or more neutrons with the release of energy 3 Explain how the neutrons produced in fission create a chain reaction and that this is controlled in a nuclear reactor, including the action of coolant, moderators and control rods 5.2.5 Half-life 1 Define the half-life of a particular isotope as the time taken for half the nuclei of that isotope in any sample to decay; recall and use this definition in calculations, which may involve information in tables or decay curves 2 Describe the dating of objects by the use of 14C 3 Explain how the type of radiation emitted and the half-life of the isotope determine which isotope is used for applications including: \(a) household fire (smoke) alarms \(b) irradiating food to kill bacteria \(c) sterilisation of equipment using gamma rays \(d) measuring and controlling thicknesses of materials with the choice of radiations used linked to penetration and absorption \(e) diagnosis and treatment of cancer using gamma rays 5.2.6 Safety precautions 1 State the effects of ionising nuclear radiations on living things, including cell death, mutations and cancer 2 Explain how radioactive materials are moved, used and stored in a safe way, with reference to: \(a) reducing exposure time \(b) increasing distance between source and living tissue \(c) use of shielding to absorb radiation6 Space physics 6.1 Earth and the Solar System 6.1.1 The Earth 1 Know that: \(a) the Earth is a planet that orbits the Sun once in approximately 365 days \(b) the orbit of the Earth around the Sun is an ellipse which is approximately circular \(c) the Earth rotates on its axis, which is tilted, once in approximately 24 hours \(d) it takes approximately one month for the Moon to orbit the Earth \(e) it takes approximately 500s for light from the Sun to reach the Earth 2 Define average orbital speed from the equation v = 2π r T where r is the average radius of the orbit and T is the orbital period; recall and use this equation 6.1.2 The Solar System 1 Describe the Solar System as containing: \(a) one star, the Sun \(b) the eight named planets and know their order from the Sun \(c) minor planets that orbit the Sun, including dwarf planets such as Pluto and asteroids in the asteroid belt \(d) moons, that orbit the planets \(e) smaller Solar System bodies, including comets and natural satellites 2 Analyse and interpret planetary data about orbital distance, orbital period, density, surface temperature and uniform gravitational field strength at the planet's surface 3 Know that the strength of the gravitational field: \(a) at the surface of a planet depends on the mass of the planet \(b) around a planet decreases as the distance from the planet increases 4 Know that the Sun contains most of the mass of the Solar System and that the strength of the gravitational field at the surface of the Sun is greater than the strength of the gravitational field at the surface of the planets 5 Know that the force that keeps an object in orbit around the Sun is the gravitational attraction of the Sun 6 Know that the strength of the Sun's gravitational field decreases and that the orbital speeds of the planets decrease as the distance from the Sun increases6.2 Stars and the Universe 6.2.1 The Sun as a star 1 Know that the Sun is a star of medium size, consisting mostly of hydrogen and helium, and that it radiates most of its energy in the infrared, visible and ultraviolet regions of the electromagnetic spectrum 2 Know that stars are powered by nuclear reactions that release energy and that in stable stars the nuclear reactions involve the fusion of hydrogen into helium 6.2.2 Stars 1 State that: \(a) galaxies are each made up of many billions of stars \(b) the Sun is a star in the galaxy known as the Milky Way \(c) other stars that make up the Milky Way are much further away from the Earth than the Sun is from the Earth \(d) astronomical distances can be measured in light-years, where one light-year is the distance travelled in a vacuum by light in one year 2 Describe the life cycle of a star: \(a) a star is formed from interstellar clouds of gas and dust that contain hydrogen \(b) a protostar is an interstellar cloud collapsing and increasing in temperature as a result of its internal gravitational attraction \(c) a protostar becomes a stable star when the inward force of gravitational attraction is balanced by an outward force due to the high temperature in the centre of the star \(d) all stars eventually run out of hydrogen as fuel for the nuclear reaction \(e) most stars expand to form red giants and more massive stars expand to form red supergiants when most of the hydrogen in the centre of the star has been converted to helium \(f) a red giant from a less massive star forms a planetary nebula with a white dwarf at its centre \(g) a red supergiant explodes as a supernova, forming a nebula containing hydrogen and new heavier elements, leaving behind a neutron star or a black hole at its centre \(h) the nebula from a supernova may form new stars with orbiting planets 6.2.3 The Universe 1 Know that the Milky Way is one of many billions of galaxies making up the Universe and that the diameter of the Milky Way is approximately 100000 light-years 2 Describe redshift as an increase in the observed wavelength of electromagnetic radiation emitted from receding stars and galaxies 3 Know that the light from distant galaxies shows redshift and that the further away the galaxy, the greater the observed redshift and the faster the galaxy's speed away from the Earth 4 Describe, qualitatively, how redshift provides evidence for the Big Bang theory