science unit 2 Flashcards

1
Q

parts must function well together for the system to run

A

smoothly.

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

a system is a

A

group of related parts that work together

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

Natural systems exist in nature and

A

were not created by humans.

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

The solar system is a

A

natural system.

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

A system has certain characteristics:

A

It has a structure.
The parts of the system are connected to make a whole.
Elements enter the system (inputs), and elements leave the system (outputs).
It has a process that gives a result.

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

A subsystem is a

A

smaller system within a larger system.

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

human-made satellites—

A

machines placed in orbit around Earth to collect information

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

spacecraft—

A

vehicles designed to travel to outer space for communication and exploration

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

orbital debris—

A

human-made objects in orbit around Earth that no longer serve a purpose

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

Like Earth, all planets are pulled into their orbit by the Sun’s

A

gravitational force.

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

The difference in gravity also causes the planets to travel in different

A

orbital paths.

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

What force does Earth use when it pulls every object near its surface?

A

a downward gravitational force.

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

The gravitational force acting on an object is called its

A

weight.

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

What does the weight of an object depend on?

A

mass

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

But because the Moon’s gravitational force is weaker than Earth’s, your weight on the Moon would be about

A

one-sixth your weight on Earth.

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

As the Moon revolves around Earth, one part of the planet always faces the

A

Moon.

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

What are the Earth’s geographic poles?

A

The North Pole and the South Pole.

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

The act of spinning around an axis is called

A

rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Each rotation takes

A

one day, or 24 hours

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

As it rotates on its axis, half of Earth faces the Sun while the other half faces

A

away from the Sun.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

It is day on the part that

and night on the part that

A

faces the Sun

faces away from the Sun.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is it called when the Earth goes around the Sun?

A

a revolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

For Earth to complete one revolution around the sun, it takes

A

365 1/4 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

That ¼ day adds up to an extra full day every four years. So, every fourth year, our calendar has

A

366 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the equator?

A

The imaginary line around Earth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The equator divides Earth into the

A

Northern and Southern Hemispheres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

when a hemisphere tilts toward the Sun, they experience

The days are

and the temperature is

A

summer

longer

warmer

27
Q

that leaves the other hemisphere tilted away from the Sun, so they experience

The days are

and the temperature is

A

winter

shorter

colder

28
Q

when the Sun lines with the equator

A

one hemisphere experiences autumn and the other experiences spring

29
Q

An orbit that is farthest from the sun is an

A

aphelion

30
Q

An orbit that is closest to the sun is a

A

perihelion

31
Q

What are the three layers of an inner planet?

A

crust, a mantle, and a core.

32
Q

The innermost layer is the core, which is subdivided into an inner and outer

A

core

33
Q

The mantle, or middle layer, of the inner planets is mainly made of

A

minerals with some metal oxides.

34
Q

The outermost layer is the crust. It is composed of

A

rock silicates and metals.

35
Q

The outer planets do not have a solid surface as the terrestrial planets do. They have a small, dense core of rocky material

A

surrounded by gases.

36
Q

The gases surrounding outer planets are mostly

A

hydrogen and helium.

37
Q

The cores of Jupiter and Saturn consist of an

A

iron-nickel alloy (mixture) and rock.

38
Q

The cores of Uranus and Neptune have nickel-iron

A

alloy with rocks surrounded by a layer of hot fluid.

39
Q

The fluid in the ice giant’s cores is

A

made of water, ammonia, and methane.

40
Q

All outside planets have

A

moons and rings

41
Q

Similar to planets, dwarf planets also

A

orbit the Sun.

42
Q

Dwarf planets in our solar system are mostly composed of

A

ice and have a rocky surface but no rings.

43
Q

Very few dwarf planets have

A

moons

44
Q

An atmosphere is an envelope of gas surrounding a

A

planet or other celestial body.

45
Q

Earth’s atmosphere contains gases called greenhouse gases. They consist of water vapor, carbon dioxide, methane, and other gases. When solar energy hits Earth’s atmosphere, these gases absorb extra heat, preventing it from reaching Earth’s

A

surface.

46
Q

Atmospheric pressure is

A

The pressure exerted by the weight of the atmosphere on the surface of Earth

47
Q

Satellites are objects that move around an

A

object

48
Q

The moon orbits Earth, so what does that make the Moon?

A

a natural satelite

49
Q

A volcano is a crack or hole in the surface of a

A

planet, often shaped like a cone.

50
Q

Tectonic plate activity causes

A

rift valleys

51
Q

When asteroids, comets, and other bodies collide with planets or moons,

A

they make flat or bowl-shaped depressions in the surface called craters.

52
Q

Canyons are .

A

deep, narrow valleys with steep sides

53
Q

What created the asteroids in the asteroid belt?

A

Smaller bodies between Jupiter and Mars colliding with another and breaking apart

54
Q

How many layers does the sun have?

A

six

55
Q

The Core

The Radiative Zone

The Convective Zone

The Photosphere

The Chromosphere

The Corona

A

The core is the center of the Sun. It is where all the Sun’s energy is produced.

The energy from the core travels to this zone through the movement of high-energy particles, or radiation.

The hotter gases from the base travel to the top of the zone, and the cooler gases sink to the bottom.

The photosphere is the region of the Sun that is visible to us from Earth. This layer is where energy from the interior of the Sun bubbles up and we see it as visible light.

It is about 2,000 kilometers thick.

It appears in the form of a white crown, or corona, during a total solar eclipse.

56
Q

Solar flares are

A

tremendous explosions on the Sun

57
Q

Solar flares are visible as

A

sudden, rapid, intense variations in the Sun’s brightness.

58
Q

Solar wind is a

A

continuous flow of charged particles, such as protons and electrons, from the Sun.

59
Q

When solar wind reaches Earth, charged particles and energy enter the

A

atmosphere near the poles, where the planet’s magnetic field is weakest.

60
Q

A coronal mass ejection (CME) is an

A

enormous burst of gas released from the Sun into space.

61
Q

A sunspot is a

A

dark spot that is visible on the photosphere.

62
Q

Near-Earth objects are

A

objects that aren’t planets, but have orbits that bring them into the inner solar system.

63
Q

What is the main cause of an aurora?

A

when solar wind enters Earth’s atmosphere, and particles interact with ions

64
Q

A white dwarf cools down to become a

A

black dwarf.

65
Q

A white dwarf is the

A

result of the core collapse of a low-mass star that sheds its outer layers.