Question 1:
Topic 1(a)(i)) – B7.1 (Human Nutrition – Diet)
(a)(ii)- B7.1 (Human Nutrition – Diet)
(b)(i)- B4.1 (Biological Molecules)
(b)(ii)- B4.1 (Biological Molecules)
(b)(iii)– B7.1 (Human Nutrition – Diet)
(c) – B4.1 (Biological Molecules)
(a) A person keeps a food diary for one day. They photograph everything that they eat and drink in the day.
Fig. 1.1 shows an extract from the diary.
(i) Identify one food item from Fig. 1.1 that is a principal source of:
carbohydrate ………………………………………………………………………………………………………
protein ……………………………………………………………………………………………………………….
vitamins ……………………………………………………………………………………………………………..
(ii) State why it is important to drink water as part of a balanced diet.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(b) Rice is classified as a starch that provides a lot of fibre.
(i) State the colour iodine solution turns when added to starch.
………………………………………………………………………………………………………………………….
(ii) Circle the component from which starch is made.
amino acids fatty acids glucose
glycerol glycogen
(iii) Describe the importance of fibre in the diet.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(c) Olive oil is a liquid fat used for cooking food.
Tick (√) the boxes to show the three chemical elements present in all cooking oils.
▶️Answer/Explanation
Ans: 1(a)(i) rice ;
chicken ;
(green) beans / cucumber / onions / salad ;
1(a)(ii) as a solvent / any valid point ;
1(b)(i) blue-black ;
1(b)(ii) glucose circled ;
1(b)(iii) prevents constipation / keeps food moving through the gut ;
1(c) carbon, hydrogen and oxygen ticked ;
Question 2:
Topic – (a)(i) C10.1 (Chemistry of the Environment – Water)
(a)(ii) C12.3 (Experimental Techniques and Chemical Analysis – Chromatography)
(a)(iii) C4.1 (Electrochemistry – Electrolysis)
(a)(iv) C11.7 (Organic Chemistry – Polymers)
(b)(i) C12.2 (Experimental Techniques and Chemical Analysis – Acid-Base Titrations)
(b)(ii) C7.1 (Acids, Bases, and Salts – Properties of Acids and Bases)
(b)(iii) C7.1 (Acids, Bases, and Salts – Properties of Acids and Bases)
(c) C7.1 (Acids, Bases, and Salts – Properties of Acids and Bases)
(a) The list below shows some chemical processes.
chlorination chromatography cracking
crystallisation decomposition
electrolysis fractional distillation polymerisation
Identify the process from the list that is used:
(i) in the treatment of drinking water
…………………………………………………………………………………………………………………….
(ii) to separate a mixture of dyes
…………………………………………………………………………………………………………………….
(iii) to extract aluminium from bauxite
…………………………………………………………………………………………………………………….
(iv) to produce long chain molecules from monomer units.
…………………………………………………………………………………………………………………….
(b) When dilute hydrochloric acid is added to aqueous sodium hydroxide, a neutralisation reaction occurs.
Fig. 2.1 shows apparatus used to investigate the change in pH as the acid is added.
(i) State the name of apparatus A.
…………………………………………………………………………………………………………………….
(ii) State the reading on the pH meter when the dilute hydrochloric acid exactly neutralises
the aqueous sodium hydroxide.
…………………………………………………………………………………………………………………….
(iii) State the two products of the reaction shown in Fig. 2.1.
1 ……………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………….
(c) Describe what is observed when aqueous sodium hydroxide is added to blue copper(II) sulfate solution.
…………………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………………
▶️Answer/Explanation
Ans: 2(a)(i) chlorination ;
2(a)(ii) chromatography ;
2(a)(iii) electrolysis ;
2(a)(iv) polymerisation ;
2(b)(i) burette ;
2(b)(ii) 7 ;
2(b)(iii) sodium chloride ;
water ;
2(c) pale blue precipitate ;
Question 3:
Topic – (a)(i) P1.6.3 (Energy Resources)
(a)(ii) P1.6.3 (Energy Resources)
(a)(iii) P5.2.5 (Nuclear Physics – Applications and Safety Precautions)
(b)(i) P5.2.3 (Nuclear Physics – Radioactive Decay)
(b)(ii) P5.2.5 (Nuclear Physics – Applications and Safety Precautions)
(c) P5.2.4 (Nuclear Physics – Half-life)
(a) The list below shows energy sources used by power stations, to generate electricity.
coal gas hydroelectric (HEP)
nuclear petroleum
(i) State the three energy sources from the list that produce carbon dioxide when generating electricity.
1 ……………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………….
3 ……………………………………………………………………………………………………………………….
(ii) Coal is described as a non-renewable energy source.
Explain what is meant by non-renewable when describing an energy source.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(iii) State one disadvantage of using nuclear fuel to generate electricity.
………………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(b) (i) In a nuclear power station, fission of plutonium-239 nuclei takes place.
Describe what happens to the nucleus of a plutonium-239 atom during nuclear fission.
…………………………………………………………………………………………………………………….
(ii) State a safe way of storing a small sample of radioactive material.
………………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(c) Technetium-99 is a radioactive material. The half-life of technetium-99 is 6 hours.
Calculate the percentage of technetium-99 remaining in a sample after 24 hours.
percentage = ……………………………………………..
▶️Answer/Explanation
Ans: 3(a)(i) any two from:
coal
gas
petroleum ;;
3(a)(ii) only existing as a finite quantity / being used up at a faster rate than it can be replaced ;
3(a)(iii) nuclear accidents / nuclear / dangerous / harmful waste produced ;
3(b)(i) (nucleus) splits ;
3(b)(ii) in a lead lined container ;
3(c) 4 half-lives / division by 16 ;
6.25% ;
Question 4:
Topic – (a) B13.2 (Coordination and Response – Hormones)
(b) B9.4 (Transport in Animals – Blood)
(c)(i) B13.2 (Coordination and Response – Hormones)
(c)(ii) B13.2 (Coordination and Response – Hormones)
(c)(iii) B13.2 (Coordination and Response – Hormones)
(c)(iv) B13.2 (Coordination and Response – Hormones)
(d) B13.1 (Coordination and Response – Nervous System)
(a) Complete the definition of the term hormone.
A hormone is a chemical substance, produced by a ………………………………………..and carried by
the blood. It alters the activity of one or more specific target …………………………………. .
(b) State the name of the component of blood that transports hormones.
……………………………………………………………………………………………………………………………
(c) A person experiences a scary event whilst wearing a heart rate monitor.
Fig. 4.1 shows her heart rate before, during and after the event.
(i) Use Fig. 4.1 to suggest the time that the scary event takes place.
time = …………………………………….. minutes
(ii) Use Fig. 4.1 to identify the maximum heart rate of this person.
heart rate = ………………………………………….. bpm
(iii) State the name of the hormone that causes the increase in heart rate seen in Fig. 4.1.
…………………………………………………………………………………………………………………….
(iv) State two other effects of this hormone.
1 ……………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………….
(d) Complete these sentences about the human nervous system.
The nervous system consists of the central nervous system and the ……………………………………….. nervous system.
The central nervous system has two parts: the ………………………………………..
and the ……………………………………….. .
▶️Answer/Explanation
Ans: 4(a) gland ;
organs ;
4(b) plasma ;
4(c)(i) 4 (minutes) ;
4(c)(ii) 109 (bpm) ;
4(c)(iii) adrenaline ;
4(c)(iv) widened pupils ;
increased breathing rate ;
any valid point ;;
4(d) peripheral ;
brain ;
spinal cord ;
Question 5:
(a)(i) C2.5 (Atoms, Elements, and Compounds – Covalent Bonds)
(a)(ii) C5.1 (Chemical Energetics – Exothermic and Endothermic Reactions)
(a)(iii) C11.4 (Organic Chemistry – Alkanes)
(d)(i) C11.5 (Organic Chemistry – Alkenes)
(d)(ii) C11.5 (Organic Chemistry – Alkenes)
(d)(iii) C11.5 (Organic Chemistry – Alkenes)
Fig. 5.1 shows three hydrocarbon molecules, A, B and C.
(a) (i) Complete the dot-and-cross diagram of molecule C. Show the outer shell electrons only.
(ii) Molecule C is a greenhouse gas.
State the name of one other greenhouse gas.
…………………………………………………………………………………………………………………….
(b) The reaction between molecule A and oxygen is exothermic.
Describe what is meant by an exothermic reaction.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(c) State and explain which molecule A, B or C represents a molecule of ethane.
molecule …………………..
explanation …………………………………………………………………………………………………..
…………………………………………………………………………………………………………………….
(d) (i) State and explain which molecule A, B or C is unsaturated.
molecule …………………..
explanation …………………………………………………………………………………………………….
……………………………………………………………………………………………………………………..
(ii) An orange solution is used to test if a hydrocarbon molecule is unsaturated or saturated.
State the name of this orange solution.
…………………………………………………………………………………………………………………….
(iii) Describe what is observed when the solution in (ii) is reacted with an unsaturated hydrocarbon molecule.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 5(a)(i) 1 shared pair ;
all else correct ;
5(a)(ii) water vapour ; carbon dioxide ;
5(b) (thermal) energy released ;
5(c) B – no mark and
has formula C$_{2}$H$_{6}$ ;
5(d)(i) A – no mark and
has two carbons but only four hydrogens / has general formula C$_{n}$H$_{2n}$ ;
5(d)(ii) (aqueous) bromine ;
5(d)(iii) decolourises ;
Question 6:
Topic – (a)(i) P2.2.2 (Thermal Physics – Melting, Boiling, and Evaporation)
(a)(ii) P2.2.2 (Thermal Physics – Melting, Boiling, and Evaporation)
(b) P1.5.1 (Motion, Forces, and Energy – Effects of Forces)
(c)(i) P1.2 (Motion, Forces, and Energy – Motion)
(c)(ii) P1.2 (Motion, Forces, and Energy – Motion)
(d)(i) P3.1 (Waves – General Properties of Waves)
(d)(ii) P3.1 (Waves – General Properties of Waves)
(d)(iii) P3.1 (Waves – General Properties of Waves)
(a) Water vapour in the air over the sea comes from liquid water in the sea.
(i) State the name of the process by which liquid water in the sea forms water vapour in the air.
…………………………………………………………………………………………………………………….
(ii) Describe how the process named in (i) occurs. Use ideas about water molecules in your answer.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(b) Fig. 6.1 shows a boat moving at constant speed.
Four forces A, B, C and D act on the boat.
State the name of force C.
…………………………………………………………………………………………………………………….
(c) Fig. 6.2 shows a speed-time graph for the boat.
(i) Determine the speed of the boat.
speed = …………………………………………. m/s
(ii) Calculate the distance travelled by the boat in 200s.
distance = …………………………………………….. m
(d) Fig. 6.3 shows a wave similar to a water wave on the surface of the sea.
(i) Determine the wavelength of the wave.
wavelength = …………………………………………….. m
(ii) On Fig. 6.3, indicate with a double headed arrow (↕ or ↔) the amplitude of the wave.
(iii) The frequency of the wave is 0.08Hz.
Calculate how many wavefronts pass a fixed point in 25 seconds.
▶️Answer/Explanation
Ans: 6(a)(i) evaporation
6(a)(ii) fastest moving/most energetic molecules/particles ;
escape from surface ;
6(b) Weight ;
6(c)(i) 4.4 (m/s) ;
6(c)(ii) distance = speed × time (in any form symbols or words) or 4.4 × 200 or area under graph ;
880 (m) ;
6(d)(i) 8 (m) ;
6(d)(ii) amplitude correctly indicated ;
6(d)(iii) 2.0 ;
Question 7:
Topic – (a)(i) B6.1 (Plant Nutrition – Photosynthesis)
(a)(ii) B6.1 (Plant Nutrition – Photosynthesis)
(a)(iii) B6.1 (Plant Nutrition – Photosynthesis)
(b) B6.1 (Plant Nutrition – Photosynthesis)
(c) B6.1 (Plant Nutrition – Photosynthesis)
(d) B6.1 (Plant Nutrition – Photosynthesis)
(a) A student investigates photosynthesis.
The student places four plants A, B, C and D in different conditions and records whether they photosynthesise.
Table 7.1 shows her results.
(i) Use Table 7.1 to state the conditions needed for photosynthesis.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(ii) Each plant is provided with an excess of carbon dioxide.
Explain why.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(iii) State the word equation for photosynthesis.
…………………………………………………………………………………………………………………….
(b) State the name of the cell structure where photosynthesis occurs.
……………………………………………………………………………………………………………………
(c) Magnesium is an essential mineral needed by plants.
Draw three lines to link the boxes and make three correct sentences about magnesium ions in plants.
(d) State the name of the principal ion required to make amino acids in a plant.
………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 7(a)(i) light ;
chlorophyll ;
7(a)(ii) carbon dioxide is required for photosynthesis ;
7(a)(iii) carbon dioxide + water → glucose and oxygen ;;
7(b) chloroplast ;
7(c)
7(d) nitrate ;
Question 8:
Topic – (a)(i) C2.2 (Atoms, Elements, and Compounds – Atomic Structure)
(a)(ii) C2.2 (Atoms, Elements, and Compounds – Atomic Structure)
(b)(i) C6.3 (Chemical Reactions – Redox)
(b)(ii) C6.3 (Chemical Reactions – Redox)
(b)(iii) C7.2 (Acids, Bases, and Salts – Oxides)
(c) C8.4 (Periodic Table – Transition Elements)
(d)(i) C9.3 (Metals – Alloys and Their Properties)
(d)(ii) C9.1 (Metals – Properties of Metals)
(d)(iii) C2.2 (Atoms, Elements, and Compounds – Atomic Structure)
(e)(i) C4.1 (Electrochemistry – Electrolysis)
(e)(ii) C4.1 (Electrochemistry – Electrolysis)
(a) An atom of copper has a proton number of 29 and a nucleon number of 63.
(i) State the number of electrons in this copper atom. …………………………….
(ii) State the number of neutrons in this copper atom. …………………………….
(b) Copper oxide is heated with carbon. Copper and carbon dioxide are made.
(i) Write the word equation for this reaction.
(ii) In this reaction, reduction of copper in the copper oxide occurs.
Describe what is meant by the term reduction.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(iii) Explain why copper oxide is described as a basic oxide.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………….
(c) Copper is a transition element.
Transition elements have high densities, high melting points and high boiling points. They are all metals.
State one other property of a transition element.
……………………………………………………………………………………………………………………..
……………………………………………………………………………………………………………………..
(d) (i) Brass is a mixture of copper and zinc.
State the term used to describe a mixture of metals.
…………………………………………………………………………………………………………………….
(ii) Brass is more malleable than either copper or zinc.
State the meaning of the term malleable.
…………………………………………………………………………………………………………………….
(iii) State the symbols of both copper and zinc.
copper symbol ……………………
zinc symbol ……………………
(e) A metal key is covered with a layer of copper by electroplating.
(i) The key is an electrode.
State which electrode is the key.
…………………………………………………………………………………………………………………….
(ii) Suggest a suitable electrolyte for electroplating the key.
…………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 8(a)(i) 29 ;
8(a)(ii) 34 ;
8(b)(i) copper oxide + carbon → copper + carbon dioxide ;
8(b)(ii) loss of oxygen ;
8(b)(iii) metal oxide / reacts with an acid to make a salt / neutralises an acid ;
8(c) any one from:
forms coloured compounds ;
acts as catalyst ; variable valency ;
8(d)(i) alloy ;
8(d)(ii) can be beaten into shape;
8(d)(iii) Cu and Zn ;
8(e)(i) cathode / negative ;
8(e)(ii) copper (II) sulfate ;
Question 9:
Topic – (a)(i) P4.3.2 (Electricity and Magnetism – Series and Parallel Circuits)
(a)(ii) P4.2.4 (Electricity and Magnetism – Resistance)
(b)(i) P2.2.1 (Thermal Physics – Thermal Expansion)
(b)(ii) P2.2.1 (Thermal Physics – Thermal Expansion)
(c)(i) P3.4 (Waves – Sound)
(c)(ii) P3.4 (Waves – Sound)
(c)(iii) P1.6.1 (Motion, Forces, and Energy – Energy)
(a) A car has two headlamps, connected in parallel, across a 12V battery. There is one switch in the circuit which controls both lamps.
(i) Complete the circuit diagram in Fig. 9.1 to show how the two lamps and the switch are connected to the battery.
Fig. 9.1
(ii) The current passing through each lamp is 4.0A.
The potential difference across each lamp is 12V.
Calculate the resistance of each lamp.
State the unit of your answer.
resistance = …………………….. unit ……………….
(b) The car is crossing a long bridge.
Fig. 9.2 shows a gap in the road surface in the middle of the bridge.
On a hot day the temperature of the road surface increases.
(i) State what happens to the gap as the temperature increases.
…………………………………………………………………………………………………………………….
(ii) Explain why the gap is needed.
……………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………….
(c) The driver of the car notices that the sound from the engine is louder and has a higher pitch when the car accelerates up a hill.
(i) State how the amplitude of the sound wave changes when the car accelerates up the hill.
…………………………………………………………………………………………………………………….
(ii) State how the frequency of the sound wave changes when the car accelerates up the hill.
…………………………………………………………………………………………………………………….
(iii) The car gains thermal energy as it accelerates up the hill.
State two other forms of energy gained by the car as it accelerates up the hill.
1 ……………………………………………………………………………………………………………………
2 ……………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 9(a)(i) all symbols correct ;
two lamps in parallel with battery ;
switch to control both lamps ;
9(a)(ii) R = V/I (in any form symbols or words) or 12/4 ;
= 3 ;
ohms / Ω ;
9(b)(i) gap is smaller/closes ;
9(b)(ii) road/bridge needs to expand on hot day/
road/bridge could be damaged by expansion ;
9(c)(i) amplitude increases ;
9(c)(ii) frequency increases ;
9(c)(iii) kinetic (energy);
gravitational potential (energy) ;
Question 10:
Topic – (a)(i) B18.2 (Organisms and Their Environment – Food Chains and Food Webs)
(a)(ii) B18.2 (Organisms and Their Environment – Food Chains and Food Webs)
(b) B18.2 (Organisms and Their Environment – Food Chains and Food Webs)
(c) B18.1 (Organisms and Their Environment – Energy Flow)
(d) B1.1 (Characteristics of Living Organisms)
(e) B2.1 (Cells – Cell Structure)
(a) A researcher collects some information about organisms that live in a desert environment.
Fig. 10.1 is a summary of the information.
(i) Construct a food chain from the information given in Fig. 10.1.
…………………………………………………………………………………………………………………….
(ii) Table 10.1 contains the names of the organisms from Fig. 10.1 and some of the terms that can be used to describe them.
Complete Table 10.1 by placing ticks (√) in the boxes to show all the terms that describe each organism. Use only the information given in Fig. 10.1.
One row has been done for you.
(b) State the name of the type of organisms that get their energy from dead and waste organic matter.
……………………………………………………………………………………………………………………………
(c) State the name of the principal source of energy for all food chains.
……………………………………………………………………………………………………………………………
(d) Nutrition is one of the characteristics of living things.
State the name of three other characteristics.
1 ………………………………………………………………………………………………………………………………
2 ………………………………………………………………………………………………………………………………
3 ………………………………………………………………………………………………………………………………
(e) State the name of the basic building blocks of which all living organisms are made.
…………………………………………………………………………………………………………………………………
▶️Answer/Explanation
Ans: 10(a)(i) cactus → desert rats → snake → desert fox ;;
10(a)(ii)
1 mark for each correct row ;;;
10(b) decomposer ;
10(c) Sun ;
10(d) any three from:
movement ;
respiration ;
sensitivity ;
growth ;
reproduction ;
excretion ;
10(e) cells ;
Question 11:
Topic – (a) C2.1 (Atoms, Elements, and Compounds – Elements, Compounds, and Mixtures)
(b) C3.1 (Stoichiometry – Formulas)
(c) C2.4 (Atoms, Elements, and Compounds – Ions and Ionic Bonds)
(d) C2.4 (Atoms, Elements, and Compounds – Ions and Ionic Bonds)
(e) C12.5 (Experimental Techniques and Chemical Analysis – Identification of Ions and Gases)
(f) C4.1 (Electrochemistry – Electrolysis)
(a) Sodium and chlorine are elements.
Sodium chloride is a compound.
Describe what is meant by an element and a compound.
element …………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………
compound …………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(b) Sodium reacts with chlorine to make sodium chloride.
Balance the symbol equation for this reaction.
………Na + Cl$_{2}$ ………NaCl
(c) When sodium reacts with chlorine, sodium atoms become sodium ions and chlorine atoms become chloride ions.
The electron configuration of a sodium atom is 2.8.1.
The electron configuration of a chlorine atom is 2.8.7.
State the electron configuration of a sodium ion and a chloride ion.
sodium ion ………………………………………..
chloride ion ………………………………………..
(d) Describe the difference in the solubility in water of an ionic compound compared with a covalent compound.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(e) Sodium chloride contains chloride ions.
Describe the test for chloride ions and state the observation for a positive result.
test …………………………………………………………………………………………………………………………..
observation ……………………………………………………………………………………………………………….
(f) Fig. 11.1 shows the electrolysis of concentrated aqueous sodium chloride.
Complete the sentences about the electrolysis of concentrated aqueous sodium chloride.
Electrolysis is defined as the breakdown of an ionic compound when
………………………………. or in aqueous solution by the passage of ……………………………….
The gas released at the negative electrode is ………………………………. and the gas
released at the positive electrode is ………………………………. .
▶️Answer/Explanation
Ans: 11(a) element – contains only one type of atom ;
compound – contains two or more elements (chemically combined) ;
11(b) 2Na + Cl$_{2}$ → 2NaCl ;
11(c) sodium ion 2.8 ;
chloride ion 2.8.8 ;
11(d) solubility of ionic compound is greater ;
11(e) add acidified aqueous silver nitrate ;
white precipitate ;
11(f) molten ;
electricity ;
hydrogen ;
chlorine ;
Question 12:
Topic – (a) P3.3 (Waves – Electromagnetic Spectrum)
(b) P1.5.1 (Motion, Forces, and Energy – Effects of Forces)
(c)(i) P1.4 (Motion, Forces, and Energy – Density)
(c)(ii) P1.3 (Motion, Forces, and Energy – Mass and Weight)
(d)(i) P3.2.3 (Waves – Thin Converging Lens)
(d)(ii) P3.2.3 (Waves – Thin Converging Lens)
(d)(iii) P3.2.3 (Waves – Thin Converging Lens)
(a) A person standing on a warm, sunny beach is exposed to several forms of electromagnetic radiation.
Fig. 12.1 shows part of the electromagnetic spectrum.
Complete Fig. 12.1 by writing the names of the other two forms of electromagnetic radiation in the correct places.
(b) The person stands with both feet on some very soft sand on the beach.
When one foot is lifted off the sand, the other foot sinks deeper into the sand.
Explain why this happens.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(c) A sample of sand has a mass of 8000kg.
This sand has a density of 1600kg/m$^{3}$.
(i) Calculate the volume of this sample of sand.
volume = …………………………………. m$^{3}$
(ii) Show that the weight of this sample of sand is 80000N.
The gravitational field strength, g, is 10N/kg.
(d) A piece of glass has been left on the beach. The glass acts like a convex lens focusing the Sun’s rays.
Fig. 12.2 shows two rays of light passing through a convex lens.
(i) Complete the light rays in Fig. 12.2 to show how the light rays are focused by the lens.
(ii) State the name of point F.
…………………………………………………………………………………………………………………….
(iii) On Fig. 12.2, draw a double headed arrow (↔) to indicate the focal length of the lens.
▶️Answer/Explanation
Ans: 12(a)
microwaves in correct place ;
X-rays in correct place ;
12(b) area decreases ;
so pressure increases ;
12(c)(i) volume = mass / density (in any form symbols or words) or 8000 / 1600 ;
= 5 (m$^{3}$ ) ;
12(c)(ii) 8000 × 10 ;
(= 80 000 N)
12(d)(i) rays meet at focus (F) ;