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GCSE level questions on the Earth in Space

Q16.

(a) Complete the following sentences.

The Sun is a stable star. This is because the forces pulling inwards caused by gravity are in equilibrium with the forces pushing outwards caused by the energy released by nuclear fusion.

[2 marks]

(b)

(i) Write down the equation that links distance travelled (s), speed (v) and time (t).

distance = speed × time

or

s = vt

[1 mark]

(ii) The mean distance between the Sun and the Earth is 0.15 Tm.

Given that light travels at a speed of 3.0 × 108 m/s.

Calculate the time taken for light from the Sun to reach the Earth.

0.15 Tm = 0.15 x 1012 m

t = s/v

t = (0.15 x 1012 ) / (3.0 × 108 )

t = 500 s

[4 marks]

(c) Some stars are much more massive than the Sun.

Describe the life cycle of stars much more massive than the Sun, including the formation of new elements.

 

This type of question is marked in two ways:

- the examiner looks for relevant points

- but also for a logical sequence...

It is not just a 'tick fest' - but a marker does look to see how many relevant points you have made, then considers how you have strung them together to put your answer into a 'level'

Level 3:

Scientifically relevant facts, events or processes are identified

and

given in detail to form an accurate account.
5 - 6 marks
Level 2:

Scientifically relevant facts, events or processes are identified and their relevance is clear.

The account is not fully accurate
3 - 4 marks
Level 1:

Facts, events or processes are identified and simply stated but their relevance is not clear.

1 - 2 marks
Level 0:

No relevant content
0 marks

 

Indicative content:

fusion (processes in stars) produce new elements

cloud of gas / hydrogen and dust OR nebula

pulled together by gravity

causing increasing temperature (to start the fusion process)

(to become a) protostar

hydrogen nuclei fuse to form helium nuclei

and the star becomes main sequence

hydrogen begins to run out

helium nuclei fuse to make heavier elements

up to iron

the star expands (to become a)

red super giant

(the star collapses rapidly) and explodes

called a supernova

creating elements heavier than iron

and distributing them throughout the universe

leaving behind a neutron star

or a black hole.

[6 marks]

(d) Stars emit radiation with a range of wavelengths.

Tick the box that contains the property of a star that the range of wavelengths depend on.

Density  
Mass  
Temperature
Volume  

[1 mark]

(Total 14 marks)