Brainscape's Knowledge GenomeTM

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


See full index

8th Grade Science > Midterm Study Guide > Flashcards

Midterm Study Guide Flashcards

1
Q

What is a model?

A

A model is a representation of an object or system.

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

Name the three types of models and give examples of each.

A

Physical-model of car, flower, a model of a cell
Mathematical-weather map
Conceptual-big bang theory

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

Explain why a weather map of the current weather is a mathematical model.

A

It uses data to make predictions.

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

What are some limitations of models?

A

may not behave or move the same as the real thing;
may not be the same size or scale;
may not made of the same material,

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

What two things make a hypothesis valid?

A

Testable and supported by evidence

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

How many millimeters are in 5 meters?

A

5m = 5,000 millimeters

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

What is the SI unit for length, volume, mass and temperature?

A

Length- m
Volume- cm3 or L
Mass- g
Temperature- K c

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

Explain how the volume of an irregularly shaped solid can be determined using a graduated cylinder.

A

Fill the cylinder a given mark, note the level of the water. Add the object and see how much the water rises. The difference between the two marks is the volume of the object.

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

Define density? What is the equation used for calculating density?

A

Density is the amount of matter in a given volume. D=m/v

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

Calculate the density of a piece of rock that has a mass of 42 grams and a volume of 8 cm3.

A

5.25g/cm3

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

True or False: 1 ml = 1 cm3

A

True

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

Name three types of safety equipment used when dealing with hazardous chemicals.

A

Goggles, Aprons, Gloves

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

Name the steps of the scientific method in order.

A

Observation
Problem/Question
Research
Hypothesis
Experiment
Analyze
Conclusion
Share results

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

What is a scientific observation?

A

Any use of the senses to gather information.

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

The independent variable is graphed on what axis?

A

X-Axis

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

The dependant variable is graphed on what axis?

A

Y-Axis

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

Name the independent and dependent variable in the following statement, “ If the amount of sunlight a sunflower receives increases, then the plant will live longer.”

A

Amount of sunlight (IF) is the independent variable. How long the plant lives (THEN) is the dependent variable.

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

Give an example of a descriptive, comparative, and experimental investigation.

A

Comparative – comparisons made between two or more items without manipulating variables (Ex. Watching and recording a month of moon phases)
Experimental – controlled set of conditions used to test a HYPOTHESIS. A VARIABLE is manipulated (Ex. Giving more light to a plant than another of the same plant to see which grows better)
Descriptive – observations recorded but NO comparisons are made and NO variables have been manipulated (Ex. Watching and recording the activity of an animal in its environment)

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

What are each of the following tools used for? psychrometer, barometer, anemometer, spring scale, beaker, triple beam balance, graduated cylinder, thermometer.

A

Psychrometer = humidity
Barometer = air pressure
Anemometer = wind speed
Spring scale = force
Beakers = hold liquids
Triple beam balances = mass
Graduated cylinders = volume
Thermometers = temperature

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

A neap tide has the angle of the moon, sun, and earth at what angle?

A

90 degrees

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

A spring tide has the angle of the moon, sun, and earth at what angle?

A

180 degrees

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

How do high tidal ranges and low tidal ranges relate to spring and neap tides?

A

Highest tidal range during spring tides and lowest tidal range during neap tides

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

Which moon phases are associated with neap tides?

A

1st and 3rd quarter moon phases

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

Which moon phases are associated with spring tides?

A

New and Full moon phases

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

What is the difference between a waxing moon and a waning moon in terms of how the amount of light seen is changing? On which side is the light?

A

Waxing: Sunlit part of the moon grows larger , light on the right
Waning: Sunlit part of the moon gets smaller, light on the left

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

What moon phase is always between the Earth and sun?

A

New moon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What causes the seasons on Earth?

A

Axis Tilt and its revolution around the sun.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What would be different about Earth if there were not different seasons?

A

If there were no seasons it would be due to not having a tilted axis or no revolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

During ____(season) the north pole receives 24 hours of sunlight, while at the same time, the south pole is experiencing ___(season) and receives 0 hours of sunlight.

A

summer, winter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why doesn’t the equator experience seasonal temperature changes?

A

the sun continually strikes the earth at the same angle giving the equator an even amount of sunlight all year long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

List the properties of each of the three major types of galaxies

A

Spiral: huge galaxy with spiral arms radiating out from a bulge in the center; rich in gasses and dust
Elliptical: elliptical shape; contains mostly old stars; very little dust and gas so few new stars are formed
Irregular: shape does not fit any particular shape; gravity from larger spiral galaxies may distort its shape

32
Q

Where is the Milky Way in our solar system (sun, planets, moons) located?

A

Located on the outer edge of the Milky Way galaxy disc in a spiral arm. About 2/3 away from core

33
Q

How does the wavelength of electromagnetic waves relate to the amount of energy carried by the waves?

A

Shorter waves have higher frequency and more energy than longer waves

34
Q

What force holds galaxies and solar systems together?

A

Gravity

35
Q

What does the Big Bang theory say about how galaxies are moving?

A

All galaxies are moving away from each other

36
Q

Look at the Electromagnetic Spectrum below. If a moving object in space had a long wavelength, would it be moving away or towards us? Is this a red shift or blue shift?

A

Long wavelength: moving away:
Red shift

37
Q

What color is our sun, and is it high, medium, or low mass?

A

Yellow, Medium Mass

38
Q

Which type of star on this H-R Diagram is the hottest?

A

Blue star

39
Q

Which type of star is the least hot?

A

Red Dwarf

40
Q

Which type of stars on the H-R diagram are brightest?

A

Supergiants & Giants

41
Q

Which type of stars on the H-R diagram are the least bright?

A

Dwarf Stars

42
Q

What property of a star do spectroscopes (spectrometers) use to determine composition and temperature of a star?

A

Stars emit (radiate) light

43
Q

What is El Nino?

A

The periodic change in the location of warm and cool surface waters in the Pacific Ocean

44
Q

What is the Coriolis Effect?

A

The curving of a moving object’s path from a straight path due to the Earth’s rotation on its axis

45
Q

Define upwelling and tell how it affects the marine food web

A

Warm surface water is replaced by cold, nutrient-rich water from the deep ocean

46
Q

What effect can a warm surface current have on coastal climate?

A

The climate is more moderate; warm water surface currents create warmer climates in coastal areas that would otherwise be cooler

47
Q

What factors affect density of water at the poles, which causes deep ocean currents to form?

A

Decreased temperature and increased salinity

48
Q

How does the sun’s energy affect the oceans’ convection currents?

A

When the sun’s energy warms the ocean near the equator, the water will rise and move toward the poles where the water will become dense and sink. This sets up a convection current deep in the ocean.

49
Q

How does the direction of ocean currents differ in the northern hemisphere compare to the southern hemisphere?

A

Surface currents move in a clockwise direction in the northern hemisphere, and counterclockwise in the southern hemisphere.

50
Q

What is the source of energy that drives the global winds (convection of air) and surface currents (convection in water)?

A

The Sun

51
Q

—– Air rises and —– air sinks

A

warm, cool

52
Q

How does a Cold front form?

A

cold air moves under less dense warm air and pushes it up

53
Q

How does a warm front form?

A

warm, less dense air moves over cold dense air

54
Q

How does an occluded front form?

A

a warm air mass is caught between two colder air masses

55
Q

How does a stationary front form?

A

cold air mass meets a warm air mass but they do not move temporarily

56
Q

On a weather map, what is the difference in weather that occurs at a low pressure area compared to a high pressure area? Why?

A

Weather at a low pressure area is often rainy if there is enough moisture in the air. This is because as air rises and cools, it cannot hold as much water vapor as it could when it was warmer. High pressure areas are usually dry since air is not rising and cooling.

57
Q

How do you know which direction a front will move when looking at a weather map?

A

It moves in the direction the triangles or half circles are facing.

58
Q

Describe the steps in the formation of a hurricane.

A

Hurricanes form over warm water near the equator.

59
Q

What is the reason for average, moderate temperatures on the land, oceans and atmosphere?

A

Continuous motion of water and air distributes the sun’s energy.

60
Q

Why do hurricanes generally form at areas between 5°-20° north and south latitudes (near the
equator)?

A

Hurricanes form over warm water in tropical areas.

61
Q

Which general direction does the jet stream (weather) flow across the U.S.?

A

Flows west to east

62
Q

In which layer of the atmosphere will we find the jet stream?

A

In the upper troposphere and the lower part of the stratosphere.

63
Q

What causes the jet stream to shift to the north or south?

A

The differences in seasons

64
Q

What is competition?

A

Competition happens when two or more organisms try to get the same resource. example: animals compete for food and mates, plant compete for water, space, nutrients, sunlight

65
Q

What is a limiting factor? Give a few examples of limiting factors

A

Any resource that limits the size of a population. Food, water, sunlight, and air are examples.

66
Q

What is the definition of carrying capacity? Be able to identify examples.

A

The largest population that can live in the same area for a long time is known as carrying capacity.

67
Q

What are adaptations?

A

Traits that improve the chances of survival and reproduction. Some traits are favorable for a species depending on their environment.

68
Q

Why is genetic variation important within a species?

A

Genetic variation allows individuals to have their own traits in order to survive in their environment.

69
Q

What do the arrows in a food web represent?

A

The Flow of energy

70
Q

What are biotic and abiotic factors? Give examples of each.

A

Biotic-living factors in the environment
Abiotic- non living factors in the environment

71
Q

What is natural selection? What happens to a population over time if they do not have favorable traits?

A

Natural selection-process by which individuals with favorable traits survive and reproduce. The population will die out.

72
Q

A population will increase overtime if there is a decrease in ___________

A

predators diseases food resources

73
Q

What happens to available energy as you move up the food pyramid?

A

Energy consumed decreases as you move up the food web.

74
Q

In what ways could human populations adversely impact ocean systems?

A

through polluting the environment, overfishing, harming coral reefs,

75
Q

What is an artificial reef? How are artificial reefs helpful in some aquatic environments?

A

A man-made structure that is sunk deep into a coastal ocean area, providing feeding and hiding places for fish, and a place for coral and sponges to attach.

8th Grade Science (1 decks)

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