P16 - Space

Question 1

What is there within our solar system?

Answer 1

• The sun
• the eight planets
• dwarf planets that orbit around the sun

Question 2

What else is there within our solar system?

Answer 2

• Natural satellites
• the moons that orbit planets

Question 3

What is our solar system a part of?

Answer 3

Milky way galaxy

Question 4

What was the sun formed from?

Answer 4

A cloud of gas and dust (nebula) pulled together by gravitational attraction

Question 5

At the start of a star’s life cycle, how was the dust and gas drawn together and what did it cause?

Answer 5

Nebula collapses and heats up, compressing the material, core reaches a million degrees celsius and at this temperature nuclear fusion begins

Question 6

What is nuclear fusion?

Answer 6

Hydrogen nuclei fuse to form helium which starts the star’s main sequence phase

Question 7

What does this fusion lead to?

Answer 7

An equilibrium between the gravitational collapse of a star and - the expansion of a star due to fusion energy

Question 8

What is a star’s life cycle determined by?

Answer 8

The size of the star

Question 9

What is the life cycle of a star?(10)

Answer 9

• Nebula
• protostar
• main sequence star
• red giant
• white dwarf
• black dwarf OR red supergiant
• supernova
• neutron star OR black hole

Question 10

What do fusion processes in stars produce?

Answer 10

All of the naturally occurring elements

Question 11

What is produced in a supernova?

Answer 11

Elements heavier than iron

Question 12

What does a supernova do?

Answer 12

Distributes the elements throughout the universe

Question 13

What is a supernova?

Answer 13

The explosion of a massive star

Question 14

How does nuclear fusion produce new elements?

Answer 14

• Two light nuclei collide at high speed and fuse
• creating a larger, heavier nucleus which represents an element

Question 15

What does gravity provide?

Answer 15

The force that allows planets and satellites to maintain their circular orbits

Question 16

What are the similarities and differences between the planets and their moons and artificial satellites?

Answer 16

• Planets and moons are natural entities while artificial satellites are man-made and orbit planets
• natural satellites orbit planets but artificial satellites are launched into orbit by humans for specific purposes

Question 17

What happens for circular orbits?

Answer 17

The force of gravity can lead to changing velocity but unchanged speed

Question 18

What happens for a stable orbit?

Answer 18

The radius must change if the speed changes

Question 19

What is the observed increase of?

Answer 19

Wavelength of light from most distant galaxies

Question 20

What is the effect of red shift?

Answer 20

The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength

Question 21

What does red shift provide evidence for?

Answer 21

That space itself(the universe) is expanding and supports the Big Bang theory

Question 22

What is the Big Bang theory?

Answer 22

Suggests that the universe began from a very small region that was extremely hot and dense and has been expanding ever since

Question 23

What observations suggest distant galaxies are receding?

Answer 23

Observations of supernovae suggest that distant galaxies are moving away fast

Question 24

What is Hubble’s law?

Answer 24

The relationship between a galaxy’s redshift and its distance which demonstrates that the farther a galaxy is, the faster it is moving away.

Question 25

What else is evidence of an expanding universe?

Answer 25

The change of each galaxy’s speed with distance

Question 26

How are scientists able to use observations to arrive at theories like the Big Bang theory?

Answer 26

Using observations like red shift and cosmic microwave background radiation(CMBR) to build evidence

Question 27

How does CMBR show evidence for the big bang theory?

Answer 27

The CMBR is the remains of the thermal energy from the Big Bang, spread thinly across the whole universe