Topic 8 Space GCSE Physics

Question 1

What is a cycle of a star that is about the same size of the sun?

Answer 1

• cloud of dust and gas (nebula)
• protostar (force of gravity)
  -main sequence star (long stable period where the outward pressure caused by the nuclear fusion balances the force of gravity pulling everything inwards
• red giant (hydrogen runs out)
• white dwarf
• black dwarf

Question 2

What is the cycle of a star that is much bigger than the sun?

Answer 2

• cloud of dust and gas (nebula)
• protostar (force of gravity)
  -main sequence star (long stable period where the outward pressure caused by the nuclear fusion balances the force of gravity pulling everything inwards
• red super giant
• supernova
• either neutron star or black hole

Question 3

How is a protostar formed?

Answer 3

• force of gravity pulls the dust and gas together to form a protostar
• the temperature rises as the star gets denser and more particles collide with each other
• when the temperature gets high enough hydrogen nuclei undergo nuclear fusion to form helium nuclei
• this gives out energy so a star is formed

Question 4

What is the process of a main sequence star?

Answer 4

• star enters a long stable period where the outward pressure caused by the nuclear fusion that tries to expand the star balances the force of gravity pulling everything inwards

Question 5

What is the process of the red giant?

Answer 5

• hydrogen begins to run out
• the star then swells into a red giant (if it is smaller than the sun)
• it becomes red because the surface cools

Question 6

What is the process of a white dwarf?

Answer 6

• a small to medium sized star like the sun becomes unstable and ejects its outer layer of dust and gas
• this leaves behind a hot, dense solid core called a white dwarf

Question 7

What is the process of a black dwarf?

Answer 7

• as a white dwarf cools down it emits less and less energy
• when it no longer emits a significant amount it is called a black dwarf

Question 8

How is a red super giant formed?

Answer 8

hydrogen begins to run out
- the star then swells into a red super giant (if its larger than the sun)

Question 9

How is a supernova formed?

Answer 9

• big stars glow brightly again as they undergo more fusion and expand and contract several times
• they eventually explode into supernova

Question 10

How is a neutron star and black hole formed?

Answer 10

• the exploding supernova throws the outer layers of dust and gas into space leaving a very dense core called a neutron star
• if the star is massive enough it will become a black hole

Question 11

What are planets?

Answer 11

• large objects that orbit a star
• 8 in our solar system

Question 12

What are dwarf planets?

Answer 12

• planet-like objects that orbit stars but don’t reach all rules for being a planet

Question 13

What are moons?

Answer 13

• orbit planets
• type of natural satellite

Question 14

What are artificial satellites?

Answer 14

• satellites that humans have built
• orbit the earth

Question 15

P101

Answer 15

force???

Question 16

What do you see when we look at light from most distant galaxies?

Answer 16

• the wavelength has increased

Question 17

What is red shift?

Answer 17

• when wavelengths are shifted towards the red end of the spectrum

Question 18

What does red-shift suggest?

Answer 18

• suggests that the source of light is moving away from us

Question 19

What is the Big-Bang theory?

Answer 19

• all the matter in the universe occupied a very small space
• this tiny space was very dense and so was very hot
• then it exploded, space started expanding and then the expansion is still going on

Question 20

What is dark matter?

Answer 20

• name given to an unknown substance which holds the galaxies together but does not emit any electromagnetic radiation