CIE iGCSE Co-Ordinated Science P6.1 The Solar System Exam Style Questions Paper 4
Question
Asteroids are large rocks which orbit the Sun.
Fig. 6.1 shows a diagram of an asteroid.
(a) Fig. 6.2 shows the asteroid orbiting the Sun.
It takes 1245 days for the asteroid to complete one full orbit of the Sun.
The asteroid orbits in a circle 3.8 × 1011 m from the Sun.
Show that the average speed of the asteroid is 22 000 m / s.
(b) Scientists have found evidence that asteroids contain the isotope strontium-87.
(i) Strontium-87 is produced by the decay of rubidium-87.
Use correct nuclide notation to complete the decay equation for rubidium-87.
87
37Rb 87
38Sr + ……
…… ……
(ii) Fig. 6.3 shows how a sample of rubidium-87 decays.
Use Fig. 6.3 to determine the half-life of rubidium-87.
Give a suitable unit for your answer.
half-life = ………………….. unit ……………………
(iii) Asteroids are thought to be 5 billion years old.
Use Fig. 6.3 to determine the percentage of rubidium-87 that has decayed to strontium-87
in the asteroid.
percentage = …………………………………………….. %
▶️Answer/Explanation
Ans :
6(a) (1245 days =) 1.1 × 108
(s) ;
(d=) 2πr OR 2π × 3.8 × 1011 OR 2.4 × 1012 (m) ;
(distance / time) OR 2.4 × 1012 / 1.1 × 108
(= 22196 OR 22000 m / s);
6(b)(i) 0−1β;
6(b)(ii) 50 ;
billion years ;
6(b)(iii) 7 (%) ;