Brainscape's Knowledge GenomeTM

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


See full index

earth science 10 > Quiz 2 (4-6) > Flashcards

Quiz 2 (4-6) Flashcards

1
Q

What is a galaxy?

A

HUGE group of stars, gas and dust held together with gravity. There may be many billion galaxies and each contain billions of stars. 100-1000 light years across.

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

What is the closest spiral galaxy to ours?

A

Andromeda Galaxy. It is 2.5 million light years away.

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

What is a nebula?

A

a cloud of dust, gas and stars. Smaller than galaxies, approximately 10-100 light years across.

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

What are the 4 types of galaxies?

A

spiral, elliptical, barred spiral and irregular

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

What are spiral galaxies?

A

contain gas, dust and many bright stars. Looks like a pinwheel, they are relatively flat with a central bulge and 2-4 rotating arms. These account for majority of the galaxies we have observed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are barred spiral galaxies?

A

Similar to spiral, except with central bar with spiral arms extending from bar.

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

What are Elliptical Galaxies?

A

Contains very little gas or dust and older reddish stars. Looks like flat circles, can be a perfect circle or oval and account for 20% of galaxies we have observed.

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

What are irregular galaxies?

A

Contains mostly gas, dust and few stars. They have no definite shape and account for about 10% of galaxies observed.

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

What is the milky way?

A

The milky way is a barred spiral galaxy and is about 100000 light years in diameter. There is a central bulge surrounded by 4 large spiral arms. It is constantly rotating, our sun travels with galaxy at 800000 km/hr (it would take 230 million years to travel one rotation of galaxy). Surrounded by a gas halo, that is also rotating. Contains 200 billion stars. Our solar system is one of spiral arms. Giant black hope in the center, billions times larger than the sun.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How old is our sun?

A

our sun was born 4.5 billion years ago, is it young compared to over half the stars in our galaxy (10bya)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a black hole?

A

A black hole is a area of space that has no volume but has a very large amount of mass. It is formed when a supernova star collapses and the force of gravity forms a hole. Nothing can escape, not even light. We cannot see them, we only see the effects of the gravitational force that comes from an object with mass and size. They are found by looking for areas where dust, gas and stars disappear.

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

What and when was the first image of a black hole?

A

Taken on April 10, 2019. This is 87.55 million light years away.

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

What do all galaxies have in common?

A

Contain a large amount of gas and dust. They are held together by gravity and is surrounded by aa gas halo.

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

What do spiral and irregular galaxies have in common?

A

contain young and bright stars

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

What do elliptical and irregular galaxies have in common?

A

contain older reddish and dull stars.

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

What is a light year?

A

1 light year is 1.5 trillion kilometer. Keeps track of distances outside of our solar ystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do stars form?

A
  1. Nebulae: Stars form in a nebula
  2. Protostar: Gravity pulls matter together into a spinning ball
  3. Nuclear Fusion: The core increases in temperature and pressure until it ignites, creating a burning ball of gas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a star?

A

giant burning sphere of gases, mostly hydrogen molecules combines to form helium. Nuclear fusion reaction releases large amounts of heat, radiation and light energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where does nuclear fusion occur?

A

In the core of a star. Stars continue to burn as there is hydrogen to fuel nuclear fusion. As a star runs out of hydrogen, helium combines to form new elements

20
Q

How does a star get its energy to glow?

A

dusion of hydrogen into hellium, called a nuclear reaction

21
Q

What elements make up young stars?

A

70% hydrogen and 30% helium (1-10% other elements)

22
Q

What causes a star to become a supernova?

A

the star begins to run low on hydrogen and fuses other elements together until it is heavier (more dense) elements that destabilize the core of the star than it explodes

23
Q

Why do you think it takes a tremendous amount of heat and pressure to create helium (and later carbon..)

A

heat makes particles move faster, pressure forces nucleus of atoms together

24
Q

What could you infer about the age of a star if you were to find evidence of iron being present?

A

Run out of hydrogen and it fusing heavier elements. When iron is present it shows that it is near the end of the stars life.

25
Q

What are the 2 paths a star can take after nuclear fusion?

A

low mass and high mass stars

26
Q

What are low mass stars?

A

sun like stars, are stabe and long lived (billions of years)

27
Q

What is the path of a low mass star?

A

low mass star to red giant to white dwarf star to black dwarf star

28
Q

What are white dwarf stars?

A

stars slowly burn out and cool down overtime, releasing matter and gas into space. Eventually remaining core becomes white dwarf star

29
Q

What is a black dwarf star?

A

A white dwarf star turns into a brown dwarf star than once cooled completely they become a black dwarf star

30
Q

What is the path of a high mass star?

A

high mass star to red supergiant, to supernova to neutron star or black hole

31
Q

What are high mass stars?

A

are unstable and short lived (thousands or millions of years)

32
Q

What are red supergiant?

A

when high mass stars run out of fuel and cool down and expand they become red supergiants

33
Q

how does a red supergiant turn to a supernova?

A

they collapse into itself and result in a huge explosion called a supernova. From these conditions we get fusion of all remaining elements

34
Q

how do supernovas turn to neutron stars?

A

the core becomes very compacted during an explosion and forms a small super-dense rapidly spinning object called a neutron star

35
Q

how does a supernova turn to a black hole?

A

if there is enough mass than the high pressure of the supernova can form a black hole

36
Q

How do we classify stars?

A

using observable characteristics
1. size
2. luminosity (amount of light emitted
3. colour (based on temperature)

37
Q

How do we use size to classify stars?

A

compare the size of other stars to our sun, Bigger size does not always mean more mass

38
Q

How do we use luminosity to classify stars?

A

a stars luminosity is the measure of total amount of light energy it gives off, per second, Less surface area means less luminous, more surface are is more luminous

39
Q

How do we use color to classify stars?

A

the color of a star relates to its temperature, the color of the burning gas (the amount of heat) The cooler the more red it appears, the hotter the more blue it appears

40
Q

What are the star color classes?

A

class o - dark blue
class b - medium blue
class a - light blue
class f - white
class g- yellow
class k - orange
class m - red

41
Q

What spectral class does our sun belong to?

A

G as our sun is yellow, therefore it is 5500 - 6000k

42
Q

What is the Hertzsprung Russell diagram

A

The HR diagram categorizes stars based on their observable characteristics. y axis - luminosity
x axis - color (temperature)

43
Q

In the HR diagram which group includes our sun?

A

main sequence

44
Q

What are the characteristics of our sun on the HR diagram?

A

1Lsun, about 6000k and yellow

45
Q

What is the most luminous category on the HR diagram?

A

blue giants, red supergiant’s. More luminous due to their larger size and therefore more surface are to emit light

46
Q

What is the emission spectra?

A

produced when a hot gas glows giving off light

47
Q

What is the absorption spectra?

A

produced when lite light is shone through a tube of gas which absorbs some of the light. dark lines appear where certain color of spectrum are missing, they correspond to a particular element which is burned and consumed by the star

earth science 10 (2 decks)

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