Question 1

The diagram shows a periscope. A periscope is an instrument that uses mirrors to allow people to look at things from a different position. Which statement correctly describes why we can see the ball through a periscope?

Accepted Answer

1) The mirror can reflect light.. A periscope works by reflecting light using two mirrors placed at an angle. Light from the ball travels to the first mirror, reflects to the second mirror, and then reflects again into the observer's eye, allowing the ball to be seen from a different position. Mirrors are not light sources, and light travels in straight lines.

Question 2

The diagram shows the stages of a bean plant. Which of the following correctly shows the life cycle of the bean plant?

Accepted Answer

4) R → P → Q. Stage P is a young plant/seedling, stage Q is an adult plant, and stage R is a seed. The life cycle begins with a seed (R), which germinates and grows into a young plant (P), and then an adult plant (Q). The adult plant (Q) then produces new seeds (R), completing the cycle. So the correct sequence is R → P → Q.

Question 3

Study the table. Which items are not placed correctly?

Accepted Answer

3) moon and lit candle. Light sources produce their own light, while non-light sources only reflect light or do not produce light. The sun, fire, and a lit candle are light sources. The moon, pencil, and cardboard are non-light sources (moon reflects sunlight). In the given table, 'moon' is incorrectly listed under 'Light sources', and 'lit candle' is incorrectly listed under 'Non-light sources'. Therefore, 'moon and lit candle' are not placed correctly.

Question 4

Chandra kept four animals, A, B, C and D, in four different containers. These animals are at different stages of growth. The table shows the amount of food given in the beginning and the amount of food left after a week. Which animal is likely to be in the pupal stage?

Accepted Answer

2) animal B. The pupal stage in complete metamorphosis is typically a non-feeding stage. Animal B was given 20g of food and 20g was left after a week, indicating it consumed no food. This is characteristic of an animal in the pupal stage.

Question 5

A shadow play is performed by placing a puppet between a screen and a torch. The shadow cast on the screen can be made bigger by moving the _____.

Accepted Answer

1) torch closer to the puppet. To make a shadow bigger, you can either move the light source closer to the object, or move the object closer to the screen. Moving the torch closer to the puppet (object) will cause the light rays to diverge more widely around the puppet, creating a larger shadow on the screen.

Question 6

Which statements about matter are correct?
A All matter can be seen and felt.
B Things around us are made of matter.
C All matter has definite shape and definite volume.
D Matter is anything that has mass and occupies space.

Accepted Answer

3) B and D only. Statement A is incorrect because some matter, like air, cannot be seen or easily felt. Statement B is correct as matter makes up all physical objects. Statement C is incorrect because only solids have a definite shape and volume; liquids have definite volume but indefinite shape, and gases have indefinite shape and volume. Statement D is correct as the defining properties of matter are having mass and occupying space (volume). Therefore, B and D are correct.

Question 7

Alex, Brianne and Chen Xin filled a bucket with sand. They continued to pour more sand into the bucket and observed that the sand flowed out of the bucket. They made the following statements about sand. Who made the correct statement(s)?
(1) Alex only
(2) Brianne only
(3) Alex and Chen Xin only
(4) Brianne and Chen Xin only

Accepted Answer

3) Alex and Chen Xin only. Alex's statement 'Sand occupies space' is correct, as all matter (including sand) occupies space. Chen Xin's statement 'Sand has a definite volume' is also correct, as sand particles, though granular, collectively have a definite volume. Brianne's statement 'Sand is a liquid and takes the shape of the bucket' is incorrect; sand is a solid, albeit in granular form, and while it takes the *shape* of the container to some extent due to gravity, it is not a liquid. Therefore, Alex and Chen Xin made correct statements.

Question 8

Joshua has three sheets of different materials cut into shapes. He conducted an experiment in a dark room using the set-up as shown. Joshua observed a shadow of a semicircle on the screen. Which of the following is most likely correct?

Accepted Answer

3) allows most light to pass through: K, L; does not allow light to pass through: M. The observation states 'a shadow of a semicircle on the screen'. This means the object blocking the light must be opaque and have a semicircular shape. From the given sheets, only Sheet M is a semicircle. Therefore, Sheet M 'does not allow light to pass through'. Looking at the options, only option (3) correctly places M in the 'does not allow light to pass through' category. This implies K and L must allow light to pass through, and option (3) assigns them to 'allows most light to pass through'.

Question 9

Which instrument can be used to measure volume?

Accepted Answer

1) [image of measuring cylinder]. A measuring cylinder (graduated cylinder) is specifically designed to measure the volume of liquids accurately. Weighing scales (options 2 and 3) measure mass, and a ruler (option 4) measures length.

Question 10

The diagram shows object X. Which of the following would most likely be the shadow of object X?

Accepted Answer

2) A and B only. Object X is a cube with a square hole cut through its center. The shape of a shadow depends on the angle of the light source and the orientation of the object.
- Shadow A: A large square with a smaller square hole in its center. This would occur if the light source is directly in front of or behind the cube, perpendicular to the face with the hole.
- Shadow B: A solid square. This would occur if the light source is shining on a side face of the cube, where the hole is not visible from that perspective, or at certain angles that obscure the hole.
Shadows C (rectangle) and D (triangle) are unlikely for a standard cube with a central square hole. Therefore, A and B are the most likely shadows.

Question 11

We can see the chair because it _____.

Accepted Answer

2) reflects light into our eyes. Objects that are not light sources (like a chair) are seen when light from a light source (e.g., the sun or a lamp) hits them and then reflects off their surface into our eyes. The reflected light travels to our eyes, allowing us to perceive the object.

Question 12

Damien places a metal spoon in a bowl of hot soup. The metal spoon becomes hotter after a while. Which of the following explains this?

Accepted Answer

4) The metal spoon gains heat from the hot soup.. Heat always transfers from a hotter object to a colder object. The hot soup is hotter than the metal spoon, so heat transfers from the hot soup to the colder metal spoon. This process is called heat gain by the metal spoon, causing its temperature to rise.

Question 13

Which statement is correct?

Accepted Answer

2) Heat always travels from a hotter place to a colder place.. Statement (1) is incorrect; temperature is a measure of the average kinetic energy of particles, while heat is a form of energy. Statement (2) is correct; this is the fundamental principle of heat transfer, where energy flows from regions of higher temperature to regions of lower temperature. Statement (3) is incorrect; touching an object provides a subjective sensation of temperature, but accurate measurement requires a thermometer. Statement (4) is incorrect; the amount of heat in a substance depends on its mass and specific heat capacity. 500ml of water has more mass than 200ml, so it will contain more heat at the same temperature.

Question 14

Ahmad placed two test tubes X and Y with equal amounts of water at different temperatures in basins of water in the Science Room. What are the possible temperatures of the water in test tubes X and Y after five minutes?

Accepted Answer

4) 30; 25. Heat transfer will occur between the test tubes and their surrounding basin water until thermal equilibrium is reached, or at least until temperatures move closer.
- Test tube X: Water at 40°C in a basin of water at 30°C. Heat will transfer from X to the basin, so X's temperature should decrease, becoming less than 40°C but higher than 30°C (unless fully equilibriated).
- Test tube Y: Water at 15°C in a basin of water at 30°C. Heat will transfer from the basin to Y, so Y's temperature should increase, becoming more than 15°C but less than 30°C.
Checking option (4): X at 30°C (decreased from 40°C, reaching equilibrium with its basin) and Y at 25°C (increased from 15°C, approaching equilibrium with its basin). This option is plausible as it shows X reaching equilibrium and Y moving towards it.

P4 Science SA1 2023 — Catholic High

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