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Science questions, chapter 12
Nama / NameKelas / ClassTarikh / Date

Solar system

44 marks. Use Practice to check each answer as you go, or Exam to answer everything against the clock first.

Section A: objective questions

12 marks
Choose the best answer for each question.
1

Question 1

Which planet is the closest to the Sun?
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A
Mercury is the closest planet to the Sun, about 57.9 million km away (textbook p. 254).
For the teacher: Remembering, low difficulty, standard 12.1.2
Textbook p. 254
2

Question 2

Which planet is known as the ‘greenhouse’ planet because of the high content of carbon dioxide in its atmosphere?
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C
Venus has an atmosphere that is about 96.5% carbon dioxide, which traps heat.
For the teacher: Remembering, low difficulty, standard 12.1.2
Textbook p. 254
3

Question 3

What is one astronomical unit (1 A.U.)?
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B
1 A.U. is the average Earth–Sun distance, 1.5 × 10⁸ km. The distance light travels in one year is a light year.
For the teacher: Remembering, low difficulty, standard 12.1.1
Textbook p. 252
4

Question 4

Why are astronomical units and light years used to express distances in the solar system?
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D
Distances between the planets and the Sun are very great, so larger units give smaller, easier numbers.
For the teacher: Understanding, low difficulty, standard 12.1.1
Textbook p. 252
5

Question 5

A planet is 7.5 × 10⁸ km from the Sun. What is its distance in A.U.? (1 A.U. = 1.5 × 10⁸ km)
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C
7.5 × 10⁸ ÷ 1.5 × 10⁸ = 5.0 A.U.
For the teacher: Applying, medium difficulty, standard 12.1.1
Textbook p. 253
6

Question 6

A star is 2 light years from the Sun. What is the distance in km? (1 ly = 9.5 × 10¹² km)
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A
From ly to km you multiply: 2 × 9.5 × 10¹² = 19 × 10¹² = 1.9 × 10¹³ km.
For the teacher: Applying, medium difficulty, standard 12.1.1
Textbook p. 253
7

Question 7

Venus rotates from east to west. What would an observer on Venus see?
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D
Venus rotates in the opposite direction to the Earth, so the Sun rises in the west and sets in the east.
For the teacher: Understanding, low difficulty, standard 12.1.3
Textbook p. 260
8

Question 8

Diagram 1 shows the gravity on the surface of five planets. Which statement is correct?
Bar chart of gravity in m s⁻²: Mercury 3.7, Earth 9.8, Mars 3.71, Saturn 10.44, Jupiter 24.79
Diagram 1
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B
24.79 ÷ 9.8 = 2.5, so Jupiter's gravity is more than twice the Earth's. Mercury (3.7) is slightly lower than Mars (3.71), Saturn (10.44) is higher than the Earth, and Jupiter is the highest.
For the teacher: Analysing, medium difficulty, standard 12.1.3
Textbook p. 259
9

Question 9

The side of Mercury that faces the Sun is above 427 °C, but the dark side falls to −173 °C. Why?
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A
Without an atmosphere, the sunlit side heats up strongly and the dark side loses heat, so the temperatures are extreme.
For the teacher: Understanding, medium difficulty, standard 12.1.3
Textbook p. 258
10

Question 10

Venus is further from the Sun than Mercury, but its surface temperature (462 °C) is higher than the average temperature of Mercury. Which factor explains this?
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C
Carbon dioxide in the thick atmosphere of Venus causes a greenhouse effect that traps heat. This is an anomaly in the pattern that nearer planets are hotter.
For the teacher: Analysing, high difficulty, standard 12.1.3
Textbook p. 258
11

Question 11

Why does the same side of the Moon always face the Earth?
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B
The Moon rotates once on its axis and orbits the Earth in about 27 days, so we always see the same face.
For the teacher: Understanding, low difficulty, standard 12.1.4
Textbook p. 261
12

Question 12

Which of the following is NOT a reason why the Earth can support life?
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D
The Earth's air is mostly nitrogen (78%) and oxygen (21%). An atmosphere with a very high carbon dioxide content, like that of Venus, does not support life.
For the teacher: Evaluating, medium difficulty, standard 12.1.5
Textbook p. 262

Section B: structured questions

32 marks
Answer all questions. Write your answers in the spaces provided.
13

Question 13

Choose the planet that matches each description.
[1 mark] (a)Known as the ‘Red Planet’.
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Mars
Mars has reddish dust and sand on its surface.
[1 mark] (b)The largest planet in the solar system.
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Jupiter
Jupiter's mass is almost 320 times the Earth's.
[1 mark] (c)Rotates on its side because its axis is tilted at about 98°.
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Uranus
For the teacher: Remembering, low difficulty, standard 12.1.2
Textbook p. 254
14

Question 14

Jupiter is 7.78 × 10⁸ km from the Sun. (1 A.U. = 1.5 × 10⁸ km; 1 ly = 9.5 × 10¹² km)
[2 marks] (a)Calculate the distance of Jupiter from the Sun in A.U.
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Tick each point you got.
[2 marks] (b)Calculate the distance of Jupiter from the Sun in light years.
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Tick each point you got.
[1 mark] (c)Neptune is 30 A.U. from the Sun. Calculate its distance in km.
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Tick each point you got.
For the teacher: Applying, medium difficulty, standard 12.1.1
Textbook p. 253
15

Question 15

Most planets rotate from west to east.
[2 marks] (a)Name the two planets that do not rotate in the same way as the others.
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Tick each point you got.
[2 marks] (b)State the direction in which the Sun appears to rise on the Earth, and the direction in which the Earth rotates to cause this.
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For the teacher: Understanding, low difficulty, standard 12.1.3
Textbook p. 260
16

Question 16

Diagram 2 shows the gravity on the surface of five planets. The relative mass of Mars is 0.107, of Saturn 95.159 and of Jupiter 317.8 (Earth = 1).
Bar chart of gravity in m s⁻²: Mercury 3.7, Earth 9.8, Mars 3.71, Saturn 10.44, Jupiter 24.79
Diagram 2
[1 mark] (a)Explain why the gravity of Mars is lower than the gravity of the Earth.
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Tick each point you got.
[2 marks] (b)Saturn has a mass about 95 times that of the Earth, but its gravity is only slightly higher than the Earth's. Explain why.
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[2 marks] (c)How many times is the gravity of Jupiter greater than the gravity of the Earth? Give your answer to 1 decimal place.
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For the teacher: Analysing, medium difficulty, standard 12.1.3
Textbook p. 259
17

Question 17

The table shows the distance of three planets from the Sun and the time each takes to orbit the Sun.
PlanetDistance from the Sun (million km)Time to orbit the Sun
X149.6365 days
Y227.9687 days
Z778.311.9 years
[1 mark] (a)State the relationship between the distance of a planet from the Sun and the time it takes to orbit the Sun.
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Tick each point you got.
[2 marks] (b)Planet X is the Earth. Which planet, Y or Z, has the higher temperature? Give a reason.
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[1 mark] (c)Calculate the number of days Planet Z takes to orbit the Sun. (1 year = 365 days)
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Tick each point you got.
For the teacher: Analysing, medium difficulty, standard 12.1.3
Textbook p. 259
18

Question 18

Hakim says, “Mercury is the hottest planet in the solar system because it is the closest to the Sun.”
[3 marks] (a)Is Hakim correct? Give two reasons for your answer.
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[1 mark] (b)Venus is similar to the Earth in size and density, yet it has no living things. Give one reason.
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Any 1 points
Tick each point you got.
For the teacher: Evaluating, high difficulty, standard 12.1.3
Textbook p. 258
19

Question 19

Scientists want to know whether another planet could replace the Earth if its resources are used up.
[3 marks] (a)State three characteristics a planet must have to support life like the Earth.
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Any 3 points
Tick each point you got.
[2 marks] (b)Predict two effects on the Earth if it stopped rotating.
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Any 2 points
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[2 marks] (c)Suggest two actions you can take to reduce your ecological footprint.
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Any 2 points
Tick each point you got.
For the teacher: Creating, high difficulty, standard 12.1.5
Textbook p. 262