Stars and the Universe — Paper 3 · IGCSE Physics 0625

12 (a) State, in order, the names of the three planets closest to the Sun. Closest to the Sun … … Furthest from the Sun … [2] (b) Define a light-year. … … [2] (c) Jupiter is 780 000 000 000 m (7.8 # 1011 m) from the Sun. The speed of light is 300 000 000 m / s (3.0 # 108 m / s) . Calculate the time for light to travel from the Sun to Jupiter. time = … s [2] [Total: 6]

6 marks

Mark scheme: 12(a) (closest to Sun) Mercury B2 Venus (furthest from Sun) Earth 12(b) distance M1 travelled by light (in the vacuum of space) in one year A1 12(c) 2.6  103 (s) OR 2600 (s) A2 time = distance ÷ speed OR 7.8  1011 ÷ 3.0  108 (C1) OR 780 000 000 000 ÷ 300 000 000

This question in 0625/32 Feb/March 2023

12 (a) Fig. 12.1 represents the Earth and the Sun at one point in the Earth’s orbit of the Sun. night day Sun axis Fig. 12.1 (not to scale) Explain the apparent daily motion of the Sun across the sky. … … … [2] (b) List the four planets closest to the Sun in order of their distance from the Sun. One is done for you. Earth 1 … 2 … 3 … 4 … [2] (c) The Sun mostly consists of two elements. State the two elements. 1 … 2 … [2] (d) The Sun is a star in a galaxy. State the name of the galaxy. … [1] [Total: 7]

7 marks

Mark scheme: 12(a) Earth rotates / spins (on its axis) M1 (once) every 24 hours / day OR daily A1 12(b) Mercury Venus Earth Mars 3 correct planets M1 in correct order A1 12(c) hydrogen B1 helium B1 12(d) Milky Way B1

This question in 0625/31 May/June 2023

11 Fig. 11.1 represents the Sun and part of the Solar System. … Mercury … Sun … Mars Fig. 11.1 (not to scale) (a) Complete the labels on Fig. 11.1 by writing on the dotted lines. [3] (b) Complete the sentences about the Sun. The Sun consists mostly of the elements … and … . Most of the Sun’s energy is radiated in the infrared, … and … regions of the electromagnetic spectrum. [4] (c) Give an estimate for the diameter of the Milky Way galaxy. diameter = … light-years [1] [Total: 8]

8 marks

Mark scheme: 11(a) B1 …Venus……. B1 B1 Mercury ……Moon………. Sun ………Earth……… Mars 11(b) Hydrogen and B1 Helium (answers maybe in either order) B1 visible (light) and B1 Ultraviolet (answers maybe in either order) B1 11(c) 100 000 (light-years) B1

This question in 0625/31 Oct/Nov 2023

11 (a) The Sun is the star in our Solar System. Eight planets orbit the Sun. State the names of two other categories of bodies in the Solar System. 1 … 2 … [2] (b) State the name of the galaxy that includes our Solar System. … [1] (c) Describe how the light from distant galaxies gives evidence to support the Big Bang Theory. … … … … … [3] [Total: 6]

6 marks

Mark scheme: 11(a) any two from:  minor / dwarf planet(s)  asteroid(s) OR asteroid belt  comet(s)  (planetary) moon(s) B2 11(b) Milky Way (galaxy) B1 11(c) any three from:  (light from distant galaxies or it) is redshifted  compared to light on Earth  (redshift is an) increase in (the observed) wavelength (of light)  (because) galaxies are moving away / receding (from Earth) OR moving apart  (Big Bang theory predicts / has) an expanding Universe B3

This question in 0625/31 May/June 2024

11 Table 11.1 shows some information about two of the planets in the Solar System. Table 11.1 time for one name of mass of planet distance from the Sun rotation on its axis planet / kg / km / hours Venus 4.87 × 1024 108.2 × 106 5832 Earth 5.97 × 1024 149.6 × 106 24 (a) (i) Venus is a similar size to the Earth. State why the gravitational field strength at the surface of the Earth is greater than the gravitational field strength at the surface of Venus. … [1] (ii) Calculate the time, in Earth days, for one day on Venus. time = … Earth days [3] (iii) Calculate the time taken for light to travel from the Sun to Venus. The speed of light is 3.0 × 108 m / s. time taken = … s [4] (b) The star nearest to the Sun is about 4.25 light-years from the Sun. Explain what is meant by one light-year. … … [2] [Total: 10]

10 marks

Mark scheme: 11(a)(i) Earth has greater mass ORA B1 11(a)(ii) 243 (Earth days) A3 5832 ÷ 24 (C2) idea that one rotation on its axis equals one day (C1) 11(a)(iii) 360 (s) A4 108.2  109 ÷ 3.0  108 (C3) speed = distance ÷ time OR (t =) s ÷ v (C1) conversion 1 km = 1000 m (C1) 11(b) distance M1 travelled (in space) by light in one year owtte A1

This question in 0625/32 May/June 2024

11 (a) The Solar System contains a number of objects. Some of these objects are listed. asteroids planets the Moon the Sun Write these objects in order of their size. smallest largest [2] (b) Redshift is an increase in the observed wavelength of the light emitted from distant galaxies. (i) State what redshift indicates about the movement of distant galaxies. … [1] (ii) State why redshift in the light from distant galaxies supports the Big Bang Theory. … … [1] (c) (i) Define one light‑year. … [1] (ii) Scientists can send spacecraft to planets. There are many planets outside the Solar System. Suggest one reason, other than cost, why scientists do not send spacecraft to planets outside the Solar System. … … [1] (d) An electromagnetic wave travels from the Sun to the Earth in a time of 500 s. The speed of the electromagnetic wave in space is 3.0 × 108 m / s. Calculate the distance between the Sun and the Earth. distance = … m [3] [Total: 9]

9 marks

Mark scheme: 11(a) asteroids the Moon planets the Sun all 4 correct – 2 marks 2 adjacent OR first AND last boxes correct – 1 mark B2 11(b)(i) receding / moving away B1 11(b)(ii) (Universe) expanding B1 11(c)(i) distance travelled by light (in space) in one year B1 11(c)(ii) distances vast OR (planets) too far away / owtte B1 11(d) 1.5  1011 (m) A3 3.0  108  500 (C2) speed = distance  time OR (distance =) speed  time (C1)

This question in 0625/33 May/June 2024

11 (a) Fig. 11.1 shows the Moon orbiting the Earth. the Moon the Earth Fig. 11.1 (i) State the name of the force that keeps the Moon in orbit around the Earth. … [1] (ii) State the time taken by the Moon to complete one orbit of the Earth. Include the unit. time for one orbit = … unit … [1] (iii) A device on the Moon sends a radio signal to the Earth. The distance from the Moon to the Earth is 3.8 × 108 m. The speed of a radio wave is 3.0 × 108 m / s. Calculate the time the radio signal takes to travel from the Moon to the Earth. time = … s [3] (b) An astronomer observes light from a distant galaxy. She writes this conclusion: ‘The observed wavelength of light from the distant galaxy is longer than the wavelength of the light emitted by the galaxy.’ Explain how this conclusion supports the Big Bang Theory of the Universe. … … … … … … [3] [Total: 8]

8 marks

Mark scheme: 11(a)(i) gravity B1 11(a)(ii) 1 month OR 4 weeks OR 27 to 31 days B1 11(a)(iii) 1.3 (s) A3 3.8  108  3(.0)  108 (C2) (time =) distance  speed OR (t =) d  s (C1) 11(b) any three from: B3 • redshift (of light) • (galaxy is) moving away / receding • Universe is expanding • Big Bang theory predicts expanding Universe

This question in 0625/33 Oct/Nov 2024

11 (a) The Solar System includes the Sun and eight planets. (i) State the name of the force that keeps the planets in orbit around the Sun. … [1] (ii) State the name of the galaxy that includes the Solar System. … [1] (b) State the meaning of the term light-year. … … [1] (c) Describe the evidence for an expanding Universe. … … … … … [3] [Total: 6]

6 marks

Mark scheme: 11(a)(i) gravitational (force / attraction) B1 11(a)(ii) Milky Way B1 11(b) distance travelled (in the vacuum of space) by light in one year B1 11(c) any three from: B3 • redshift of light / redshift of (em) radiation (from distant / receding galaxies compared to light emitted on Earth) • an increase in the (observed) wavelength of light / em radiation (emitted from distant / receding galaxies) • the most / more distant galaxies have greater redshift than closer galaxies • more distant galaxies are moving away faster than closer galaxies

This question in 0625/31 May/June 2025

11 Fig. 11.1 represents the Solar System. The Sun and five of the eight planets are labelled. Neptune Earth … Sun Uranus Mercury … … Saturn Fig. 11.1 (not to scale) (a) Complete the three missing labels on Fig. 11.1 by writing the name of each planet on its dotted line. [2] (b) (i) The Sun consists mainly of two elements. Name the two elements. … and … [2] (ii) The Sun radiates energy mainly in three regions of the electromagnetic spectrum. Ultraviolet is one of the three regions. State the name of one of the other two regions. … [1] (c) (i) Scientists use the Big Bang Theory to explain the way the Universe began. State one piece of evidence that supports the Big Bang Theory. … … [1] (ii) Scientists use the accretion model to explain the formation of the Solar System. Complete the following sentences about the accretion model. In space, there are clouds of dust and … . The material spins around and moves closer together due to the force of … . This forms an accretion … . [3] [Total: 9]

9 marks

Mark scheme: 11(a) Venus B2 Mars Jupiter all 3 in correct position – 2 marks 1 or 2 in correct position OR all 3 named – 1 mark 11(b)(i) hydrogen B1 helium B1 11(b)(ii) visible light OR infrared B1 11(c)(i) redshift B1 11(c)(ii) gas(es) B1 gravity B1 disc B1

This question in 0625/32 May/June 2025

11 Fig. 11.1 represents the Solar System. The Sun and five of the eight planets are labelled. Neptune Earth … Sun Uranus Mercury … … Saturn Fig. 11.1 (not to scale) (a) Complete the three missing labels on Fig. 11.1 by writing the name of each planet on its dotted line. [2] (b) (i) The Sun consists mainly of two elements. Name the two elements. … and … [2] (ii) The Sun radiates energy mainly in three regions of the electromagnetic spectrum. Ultraviolet is one of the three regions. State the name of one of the other two regions. … [1] (c) (i) Scientists use the Big Bang Theory to explain the way the Universe began. State one piece of evidence that supports the Big Bang Theory. … … [1] (ii) Scientists use the accretion model to explain the formation of the Solar System. Complete the following sentences about the accretion model. In space, there are clouds of dust and … . The material spins around and moves closer together due to the force of … . This forms an accretion … . [3] [Total: 9]

9 marks

Mark scheme: 11(a) Venus B2 Mars Jupiter all 3 in correct position – 2 marks 1 or 2 in correct position OR all 3 named – 1 mark 11(b)(i) hydrogen B1 helium B1 11(b)(ii) visible light OR infrared B1 11(c)(i) redshift B1 11(c)(ii) gas(es) B1 gravity B1 disc B1

This question in 0625/33 May/June 2025

10 (a) Complete these sentences about the formation of the Solar System. (i) Planets were formed from interstellar clouds of gas and … [1] (ii) The interstellar clouds were pulled together by the force of … [1] (iii) The rotation of material in the interstellar clouds formed an accretion … [1] (b) The Big Bang Theory is a possible description of the beginning of the Universe. State one piece of evidence that supports the Big Bang Theory and explain how this evidence supports the Big Bang Theory. evidence … explanation … … … … [2] [Total: 5]

5 marks

Mark scheme: 10(a) dust B1 gravity B1 disc B1 10(b) evidence B1 red shift seen or increase in the (observed) wavelength (of electromagnetic radiation) or light appears to be shifted towards the red end of the spectrum explanation B1 • (the red shift shows) galaxies / stars / objects are moving away from each other • the Universe is expanding • all matter in the Universe once started from a single point. • more distant galaxies show a bigger red shift • more distant galaxies are moving away faster

This question in 0625/32 Oct/Nov 2025

10 (a) Each box in the left column shows a description of a unit of time. Each box in the right column shows the name of a unit of time. Draw a line to connect each description to the appropriate unit. description name The time taken for one day the Earth to rotate once on its axis. one week The time taken for the Earth to orbit the Sun once. one month The time taken for the Moon to orbit one year the Earth once. [3] (b) (i) The Sun consists mostly of two elements. State the names of the two elements. … and … [2] (ii) The Sun radiates energy mostly in three regions of the electromagnetic spectrum. One of these regions is visible light. State the name for each of the other two regions. … and … [2] [Total: 7]

7 marks

Mark scheme: 10(a) B1 B1 B1 10(b)(i) hydrogen B1 helium B1 10(b)(ii) ultraviolet B1 infrared B1

This question in 0625/33 Oct/Nov 2025