Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics A level OCR > Stars (C19) > Flashcards

Stars (C19) Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

3 stages in star formation

A

nebula
Protostar
Star

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Difference between star and protostar

A

star there is fusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe energy changes in star formation

A

GPE –> Kinetic energy
causes heating up
leads to high pressure and fusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the equilibrium in a main sequence star

A

outward gas and radiation pressure

Inwards gravitational pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name 8 space objects

A 
Star
Planet
dwarf planet
asteroid
comet
Solar system
Galaxy
Universe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

To form a red giant what size?

A

0.5 solar masses to 10 molar masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

To form a super red giant what size?

A

above 10 solar masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe how a red giant forms

A

Hydrogen fuel runs low, so radiation pressure falls, causing the sun the have excessive inward pressure
this causes fusion of hydrogen in the outer layers to occur
So the outer layers drift apart and the star swells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the life cycle of a small star

A 
Nebula
Protostar
Main-sequence star
Red giant
White dwarf and nebula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the life cycle of a large star

A 
nebula
protostar
Main-sequence
Super red giant
Neutron star or black hole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the Chandrasekhar limit

A

core of 1.44 solar masses or more will result in a neutron star/black hole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Conditions for neutron star

A

core between 1.44 solar masses and 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Conditions for blackhole

A

core greater than 3 solar masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What stops a black hole/neutron star in smaller stars from forming

A

the electron degeneracy pressure resists the gravitational force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why is there electron degeneracy pressure

A

Pauli exclusion principle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the difference between super red giant and red giant

A

in super, heavier elements up to iron can be fused

17
Q

What causes a supernova

A

super red giant starts to fuse iron, which takes more energy than it releases, causing the rapid collapse of the star and explosion

18
Q

When are elements heavier than iron fused?

A

in supernova explosions

19
Q

Where do electrons want to exist

A

at the lowest energy state (most negative)

20
Q

Key thing with energy levels

A

Only discrete, certain jumps are possible, therefore only certain frequencies are emitted/absorbed

21
Q

What is an excited electron

A

an electron that has been moved to a higher energy state

22
Q

What does 0 represent on the electron level diagrams

A

a free elctron

23
Q

why is the energy levels for electrons negative

A

energy is required to remove the electrons

24
Q

Things that are excited…

A

quickly move down to lower energy states

25
Q

What is spectroscopy

A

Analysis of light to determine the elements within a substance

26
Q

What are the 3 types of spectrum

A

Continuous
emission
absorption

27
Q

Why does a sun emit an absorption spectra

A

as the sun is a hot body so emits all wavelengths but the gasses on the surface absorb certain wavelengths

28
Q

what is an emission spectra

A

unique set of lines for each element due to the specific photons it gives off

29
Q

What is a diffraction grating

A

a device with has many slits designed to diffract light

30
Q

Why are diffraction gratings used

A

has it seperates different wavelengths of light so reduces blurriness

31
Q

What colour diffracts most in a diffraction grating

A

red

32
Q

What colour diffracts least in a diffraction grating

A

violet

33
Q

Why does different colours of light diffract different amounts

A

Depends on wavelength

34
Q

What is a blackbody

A

an abject which absorbs (and therefore emits) a full spectrum of wavelengths

35
Q

Why do hotter stars have lower peak wavelengths

A

Energy is inversely proportional to wavelength and energy is proportional to temp

36
Q

What is Weins displacement constant

A

2.9 x 10^-3 Km

37
Q

what is luminosity

A

total power radiated by a star

38
Q

What two laws are needed to calculate the size of stars

A

Wiens and stefans

39
Q

What is Stefan’s Law

A

Luminosity is proportional to the radius squared and the temperature to the power of 4

Physics A level OCR (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions