Practical skills — IGCSE Science - Combined (0653) questions by topic
Planning a full investigation, controlling variables, and reading or plotting data are the backbone of this topic: choosing temperature rather than ice-cube quantity as the independent variable, defining graph axes correctly, and comparing ECG traces mark by mark. Calculate, record and describe are the leading command words, each demanding a specific value, unit or labelled feature rather than a general comment.
With 96 real questions from 2023 to 2025 papers and marks ranging from 1 to 13, this is the largest set in the syllabus, so practice needs to be varied rather than repetitive. Submitting graphs and written methods for instant marking catches specific slips fast, such as an axis without units or points joined dot-to-dot instead of a drawn curve.
What examiners look for
- A frequent error is choosing the number or mass of ice cubes as the independent variable, when temperature is the variable that should be changed.
- Graphs commonly lose marks for missing axis labels or units, or for inverting the axes altogether.
- Reports note candidates joining plotted points dot-to-dot rather than drawing a curve as the instructions require.
- ECG description answers often fail to state which part, by letter, and which trace is being discussed, or to describe both an increase and the later plateau at 144 bpm.
- Strong responses vary at least five values of the independent variable, keep other quantities such as ice-cube size and juice volume constant, and label graph axes with the correct quantities and units.
May–June 2025, Paper 11
Which piece of apparatus is used to measure exactly 20.6 cm^3 of water? A measuring cylinder B burette C graduated beaker D syringe
Answer this question and get it marked →A student determines the density of a small, irregularly shaped rock. Which apparatus does the student use? A balance, measuring cylinder and ruler B balance and measuring…
Answer this question and get it marked →May–June 2025, Paper 13
A stop-watch is used to record the time at two points in a race. The diagram shows the readings. Reading 1 shows 00:01:58 (h:min:s) and reading 2 shows 00:03:04 (h:min:s). What is…
Answer this question and get it marked →May–June 2025, Paper 21
A student determines the resistance of resistor R. Which circuit is used to obtain the readings needed? A an ammeter connected in series with R and a voltmeter connected in…
Answer this question and get it marked →May–June 2025, Paper 23
The diagram shows the scale of an analogue voltmeter. The scale runs from 0 to 0.5 V with major divisions marked at 0, 0.1, 0.2, 0.3, 0.4 and 0.5 V, each major division subdivided…
Answer this question and get it marked →May–June 2025, Paper 51
You are going to investigate the nutrient content of three drinks, A, B and C. Procedure step 1 Add approximately 3 cm^3 of drink A to a clean test-tube. step 2 Add a few drops of…
Answer this question and get it marked →Invertase is an enzyme. Invertase breaks down the non-reducing sugar sucrose into reducing sugars. non-reducing sugar sucrose --[invertase]-- reducing sugars Benedict's solution…
Answer this question and get it marked →You are going to investigate aqueous H. Investigating the rate of reaction of aqueous H with magnesium. Procedure step 1 Measure 25 cm^3 of aqueous H using a measuring cylinder.…
Answer this question and get it marked →You are going to determine the period T of a pendulum. The apparatus shown in Fig. 4.1 has been set up for you. Fig. 4.1 shows a pendulum hanging from a clamp on a stand resting…
Answer this question and get it marked →May–June 2025, Paper 52
You are going to investigate a root vegetable. You are provided with a section of carrot root on a white tile. In the box, make a large pencil drawing of the cut surface of the…
Answer this question and get it marked →You are going to investigate the reaction between aluminium and aqueous copper(II) chloride. Aqueous copper(II) chloride is a blue solution. Procedure - Assemble the apparatus…
Answer this question and get it marked →You are going to investigate the behaviour of resistors in a series circuit. The circuit shown in Fig. 3.1 has been set up for you. It is a series circuit containing a power…
Answer this question and get it marked →Fig. 4.1 shows a metal rod placed vertically in a box of sand, with a mass held above the rod ready to be dropped onto it. Labels: mass, sand, metal rod. When a mass is dropped…
Answer this question and get it marked →May–June 2025, Paper 61
A student investigates the nutrient content of three colourless drinks, A, B and C. Procedure The student: step 1 adds 2 cm3 of drink A, drink B and drink C to separate clean…
Answer this question and get it marked →A student investigates aqueous H. Part (a): investigating the rate of reaction of aqueous H with magnesium. Procedure The student: step 1 pours 25 cm3 of aqueous H into a beaker…
Answer this question and get it marked →A student investigates the period T of a pendulum. Fig. 4.1 shows a bob attached to a string. The string is clamped so that the centre of the bob is a distance x above the bench.…
Answer this question and get it marked →May–June 2025, Paper 62
A student investigates a root vegetable. Fig. 1.1 shows a section cut through the root of a carrot. In the box, make a large pencil drawing of the cut surface of the carrot root.
Answer this question and get it marked →A student investigates the reaction between aluminium and aqueous copper(II) chloride. Aqueous copper(II) chloride is a blue solution. Aluminium is a grey solid. Procedure The…
Answer this question and get it marked →A student investigates an electrical circuit with two identical resistors in series. Procedure The student: step 1 connects the circuit shown in Fig. 3.1 step 2 connects a…
Answer this question and get it marked →Fig. 4.1 shows a metal rod placed in a box of sand. A mass is held above the rod. The metal rod stands vertically with its lower end pushed into a layer of sand in a tray; the…
Answer this question and get it marked →May–June 2025, Paper 63
A student investigates the effect of oxygen concentration on the germination of pea seeds. The student assembles the apparatus shown in Fig. 1.2 and leaves the five flasks for…
Answer this question and get it marked →Aqueous ammonium carbonate reacts with aqueous barium nitrate to form a white precipitate of barium carbonate. aqueous ammonium carbonate + aqueous barium nitrate - barium…
Answer this question and get it marked →A student investigates the rate of cooling of hot water in two glass beakers P and Q. Each beaker has a circular open top with a different diameter. Fig. 4.1 shows the water in…
Answer this question and get it marked →May–June 2024, Paper 51
You are going to investigate the effect of copper sulfate on the enzyme amylase (amylase speeds up the breakdown of starch into the sugar maltose; the reaction is followed using…
Answer this question and get it marked →You are going to investigate the reaction of sodium hydrogencarbonate with dilute sulfuric acid (this reaction produces carbon dioxide gas). Put 50 cm3 of dilute sulfuric acid…
Answer this question and get it marked →You are going to determine the density of a wooden block. Fig. 3.1 shows a wooden block with height h, width w and length l. Measure the height h, width w and length l of your…
Answer this question and get it marked →A thermistor is a type of variable resistor used to measure changes in the temperature of water in a beaker. The resistance R of the thermistor at temperature T is calculated…
Answer this question and get it marked →May–June 2024, Paper 52
You are going to investigate the effect of enzyme concentration on the breakdown of a substance. Catalase (an enzyme found in peas) breaks down hydrogen peroxide into water and…
Answer this question and get it marked →When an aqueous salt solution is left in an open container, the mass of the solution decreases because some of the water evaporates. Plan an investigation to determine the…
Answer this question and get it marked →You are going to compare the rate at which hot water cools in a beaker with and without a lid (a cardboard disc with a small hole). Arrange the equipment as in Fig. 4.1. Add 100…
Answer this question and get it marked →May–June 2024, Paper 61
A student investigates the effect of copper sulfate on the enzyme amylase (amylase breaks down starch into maltose; the reaction is followed using iodine solution). The student…
Answer this question and get it marked →A student investigates the reaction of sodium hydrogencarbonate with dilute sulfuric acid (producing carbon dioxide). The student adds one spatula of sodium hydrogencarbonate to…
Answer this question and get it marked →A student determines the density of a wooden block. Fig. 3.1 shows the wooden block drawn to actual size, with height h, width w and length l. Measure the height h, width w and…
Answer this question and get it marked →A thermistor is a type of variable resistor used to measure changes in the temperature of water in a beaker. The resistance R of the thermistor at temperature T is calculated…
Answer this question and get it marked →May–June 2024, Paper 62
When an aqueous salt solution is left in an open container, the mass of the solution decreases. This is because some of the water evaporates. Plan an investigation to determine…
Answer this question and get it marked →A student compares the rate at which hot water cools in a beaker with and without a lid. The apparatus used for the beaker without a lid is shown in Fig. 4.1 (a beaker of water…
Answer this question and get it marked →May–June 2024, Paper 63
When seeds germinate, they use oxygen gas for aerobic respiration. glucose + oxygen → carbon dioxide + water When placed in a test-tube as shown in Fig. 2.1, the seeds use up…
Answer this question and get it marked →A student determines the mass M of a metre rule. (a) The apparatus is shown in Fig. 4.1. The metre rule rests on a pivot at the 20.0 cm mark. The other end of the metre rule is…
Answer this question and get it marked →October–November 2024, Paper 51
You are provided with one half of an onion on a white tile. (a) In the box, make a large and detailed pencil drawing of the cut surface of the onion.
Answer this question and get it marked →Plants such as onions need minerals in the soil to grow. Fig. 2.1 shows an onion plant. Plan an investigation to determine the relationship between the concentration of minerals…
Answer this question and get it marked →You are going to investigate the white solid provided, solid H. (a) Procedure: step 1 Measure the mass of an empty test-tube. Record this value in Table 3.1. step 2 Place three…
Answer this question and get it marked →You are going to investigate the stretching of identical springs. The apparatus has been assembled for you as shown in Fig. 4.1 (a metre rule clamped vertically between two clamp…
Answer this question and get it marked →October–November 2024, Paper 52
You are provided with one half of an onion on a white tile. (a) In the box, make a large and detailed pencil drawing of the cut surface of the onion.
Answer this question and get it marked →Plants such as onions need minerals in the soil to grow. Fig. 2.1 shows an onion plant. Plan an investigation to determine the relationship between the concentration of minerals…
Answer this question and get it marked →You are going to investigate the white solid provided, solid H. (a) Procedure: step 1 Measure the mass of an empty test-tube. Record this value in Table 3.1. step 2 Place three…
Answer this question and get it marked →You are going to investigate the stretching of identical springs. The apparatus has been assembled for you as shown in Fig. 4.1 (a metre rule clamped vertically between two clamp…
Answer this question and get it marked →October–November 2024, Paper 53
You are provided with one half of an onion on a white tile. (a) In the box, make a large and detailed pencil drawing of the cut surface of the onion.
Answer this question and get it marked →Plants such as onions need minerals in the soil to grow. Fig. 2.1 shows an onion plant. Plan an investigation to determine the relationship between the concentration of minerals…
Answer this question and get it marked →You are going to investigate the white solid provided, solid H. (a) Procedure: step 1 Measure the mass of an empty test-tube. Record this value in Table 3.1. step 2 Place three…
Answer this question and get it marked →You are going to investigate the stretching of identical springs. The apparatus has been assembled for you as shown in Fig. 4.1 (a metre rule clamped vertically between two clamp…
Answer this question and get it marked →October–November 2024, Paper 61
Fig. 1.1 is a photograph showing the cut surface of an onion (with horizontal points A and B marked at the widest part). (a) In the box, make a large and detailed pencil drawing…
Answer this question and get it marked →Plants such as onions need minerals in the soil to grow. Fig. 2.1 shows an onion plant. Plan an investigation to determine the relationship between the concentration of minerals…
Answer this question and get it marked →A student investigates a white solid, solid H. Procedure: step 1 measures the mass of an empty test-tube and records the value in Table 3.1 step 2 places some solid H into the…
Answer this question and get it marked →A student investigates the stretching of a pair of identical springs. The student assembles the apparatus as shown in Fig. 4.1 (a metre rule clamped vertically between two clamp…
Answer this question and get it marked →October–November 2024, Paper 62
A student uses the apparatus shown in Fig. 1.1 to compare the energy content of two different types of food, A and B. (Apparatus: a boiling tube containing 20 cm³ water held in a…
Answer this question and get it marked →A student investigates a white solid, H. (a) The student investigates the relationship between the mass of H added to water and the temperature increase it produces. Procedure:…
Answer this question and get it marked →A student investigates the refraction of light through a semi-circular glass block. Procedure: draws a straight line AB down the centre of a sheet of white paper; draws a straight…
Answer this question and get it marked →Fig. 4.1 shows a spring of diameter D made using a coil of metal wire. The spring stretches with an extension x when a load F is applied to the spring. The spring constant k is a…
Answer this question and get it marked →October–November 2024, Paper 63
A student prepares a pure dry sample of the insoluble salt, barium sulfate. Procedure: step 1 puts 75 cm³ of aqueous sodium sulfate into a beaker; step 2 adds an excess of aqueous…
Answer this question and get it marked →Antacids are used to neutralise excess acid in the stomach. Stomach acid has a pH of 2. When antacid is added to stomach acid, the pH increases. Plan an investigation to determine…
Answer this question and get it marked →A student investigates the effects of two factors on the period T of a simple pendulum. The period T of a pendulum is the time for one oscillation (swing). Fig. 4.1 shows a…
Answer this question and get it marked →May–June 2023, Paper 31
A student measures the melting point of some salty water and some pure water. Table 2.1 shows the results: salty water melting point –5 °C; pure water 0 °C. State the name of one…
Answer this question and get it marked →May–June 2023, Paper 33
A student investigates the combustion of natural gas (Fig. 2.1: a beaker of water heated by burning natural gas). The student measures the temperature of the water as the natural…
Answer this question and get it marked →May–June 2023, Paper 51
You will estimate the concentration of vitamin C in a sample of fruit juice. When iodine solution is added to a mixture of starch and fruit juice, the starch turns the iodine…
Answer this question and get it marked →You will investigate the components of a fertiliser, which contains an insoluble substance and a soluble salt. Procedure: pour all of the fertiliser into a beaker, add about 20…
Answer this question and get it marked →Cetyl alcohol is a white solid with a melting point of 49 °C; if salt is mixed with cetyl alcohol the melting point decreases. Some apparatus needed to determine the melting point…
Answer this question and get it marked →You will investigate the resistance of different combinations of two identical lamps L and M. Fig. 4.1 shows a circuit using lamp L (power supply, switch, ammeter A, voltmeter V…
Answer this question and get it marked →May–June 2023, Paper 52
You are going to investigate okra, a fruit which contains many seeds; you are provided with a section of okra on a white tile. In the box provided, draw a large, clear pencil…
Answer this question and get it marked →The enzyme amylase breaks down starch to form a reducing sugar. Plan an investigation to determine the relationship between temperature and the time taken to completely break down…
Answer this question and get it marked →You are going to investigate a white solid H. Procedure: measure the mass of the clean dry test-tube labelled H and record in Table 3.1; place two spatula loads of solid H into…
Answer this question and get it marked →You are going to measure the focal length F of a convex lens. Arrange the equipment as in Fig. 4.1 (illuminated triangular object at 0 cm, lens at distance u, screen at distance…
Answer this question and get it marked →May–June 2023, Paper 61
A student estimates the concentration of vitamin C in a sample of fruit juice. When iodine solution is added to a starch + fruit juice mixture, the starch turns the iodine…
Answer this question and get it marked →A student investigates the components of a fertiliser containing insoluble sand and a soluble salt, starting with 5.00 g of fertiliser. Procedure: add distilled water in a beaker,…
Answer this question and get it marked →Cetyl alcohol is a white solid with a melting point of 49 °C; if salt is mixed with cetyl alcohol the melting point decreases. Some apparatus needed to determine the melting point…
Answer this question and get it marked →A student investigates the resistance of different combinations of two identical lamps L and M. Fig. 4.1 shows a circuit using lamp L (power supply, switch, ammeter A, voltmeter V…
Answer this question and get it marked →May–June 2023, Paper 62
Fig. 1.1 is a section through okra, a fruit which contains five seeds (with points A and B marked across a diameter). In the box provided, draw a large, clear pencil drawing of…
Answer this question and get it marked →The enzyme amylase breaks down starch to form a reducing sugar. Iodine is a brown solution that turns blue/black in the presence of starch. Plan an investigation to determine the…
Answer this question and get it marked →A student investigates a white solid H. Procedure: measure the mass of an empty test-tube (16.23 g, recorded in Table 3.1); place some solid H into the test-tube; measure the mass…
Answer this question and get it marked →A student determines the focal length F of a convex lens (Fig. 4.1: illuminated triangular object at 0 cm, lens at distance u, screen at distance v, total distance D, on a metre…
Answer this question and get it marked →May–June 2023, Paper 63
A student investigates the effect of temperature on the growth of mushrooms. Fig. 1.1 shows a section through a mushroom (with the cap labelled). In the box provided, make a…
Answer this question and get it marked →A student investigates a green solid H. Procedure: add some dilute hydrochloric acid to solid H in a test-tube; the mixture forms a blue solution; do a flame test on the blue…
Answer this question and get it marked →A student investigates the period of oscillation of a spring with different loads. The period is the time for one oscillation, measured by displacing the spring downwards,…
Answer this question and get it marked →A student rolls a toy car down a ramp of height h. At the bottom of the ramp, the car rolls a distance d along the horizontal floor until it stops (Fig. 4.1). Plan an…
Answer this question and get it marked →October–November 2023, Paper 51
You are going to investigate the effect of an enzyme used in the large-scale production of apple juice. Apple puree is placed in two boiling tubes E and W; 10 cm3 of enzyme…
Answer this question and get it marked →You are going to investigate the rate of reaction between magnesium and dilute hydrochloric acid. Add 25.0 cm3 of dilute hydrochloric acid to a 100 cm3 beaker, cut a 5 mm length…
Answer this question and get it marked →You are going to investigate the reflection of light by a plane mirror. Fig. 3.1 shows a horizontal line XZ. Line NY is the normal to line XZ at point Y. Line AY meets line XZ at…
Answer this question and get it marked →Plan an investigation to determine the relationship between the temperature of apple juice and the time it takes for ice cubes to melt when added to it. You are provided with: ice…
Answer this question and get it marked →October–November 2023, Paper 61
A student investigates the effect of an enzyme used in the large-scale production of apple juice. Apple puree is added to test-tubes E and W; 10 cm3 of enzyme is added to E and 10…
Answer this question and get it marked →A student investigates the reflection of light by a plane mirror. Fig. 3.1 shows a horizontal line XZ. Line NY is the normal to line XZ at point Y. Line AY meets line XZ at point…
Answer this question and get it marked →Plan an investigation to determine the relationship between the temperature of apple juice and the time it takes for ice cubes to melt when added to it. You are provided with: ice…
Answer this question and get it marked →October–November 2023, Paper 62
A student investigates the effect of exercise on the heart rate of a fit and healthy person, using an electrocardiogram (ECG) to record heart beats. Fig. 1.1 shows an ECG for one…
Answer this question and get it marked →A student investigates the reaction between iron and a dilute acid (slow at room temperature). The student adds dilute acid to a boiling tube, adds excess iron powder, stirs, and…
Answer this question and get it marked →Citric acid reacts with aqueous sodium hydroxide as shown: citric acid + sodium hydroxide → sodium citrate + water. In the reaction, aqueous sodium hydroxide is neutralised by…
Answer this question and get it marked →A student compares the conducting properties of metal and glass using the apparatus in Fig. 4.1 (a metal container and a glass beaker, a thermometer, clamp stand). The student…
Answer this question and get it marked →October–November 2023, Paper 63
Urease is an enzyme that breaks down urea in solution to form aqueous ammonia. Urea in solution is almost neutral; the aqueous ammonia formed increases the pH of the solution.…
Answer this question and get it marked →A student investigates the magnification of a thin converging lens using the apparatus in Fig. 4.1 (light source, object at object distance u, lens, image at image distance v,…
Answer this question and get it marked →Other IGCSE Science - Combined topics
- Motion, forces and energy (53)
- Electricity and magnetism (38)
- Waves (32)
- Human nutrition (23)
- Acids, bases and salts (22)
- Organisms and their environment (21)
- Organic chemistry (21)
- Reproduction (20)
- Thermal physics (20)
- Plant nutrition (19)
- The Periodic Table (18)
- Metals (18)