Science Exam S1

Question 1

What is an independent variable?

Answer 1

The variable that does not depend on anything.

Question 2

What is the dependent variable?

Answer 2

The variable that depends on the independent variable.

Question 3

What is a constant?

Answer 3

Something that must stay the same over testing for accurate results.

Question 4

Situation: You are asked to test how different types of surfaces affect how fast a soccer ball rolls down a ramp. What are independent/dependent variables and constants?

Answer 4

-Independent: surface of the ramp
-Dependent: how fast the soccer ball rolls
-Constants: the angle of the ramp, the length of the ramp, the height of the ramp, the soccer ball size and shape, the age of the soccer ball, etc.

Question 5

You are researching how temperature affects how fast a pop loses its fizziness. What is the independent/dependent variable and constants?

Answer 5

-Independent: temperature
-Dependent: how fast pop loses its fizziness.
-Constants: room, type of pop, container of pop, etc.

Question 6

How do you write a good science question?

Answer 6

How does the independent variable affect the dependent variable?

Question 7

What makes science data reliable?

Answer 7

controlled variables, multiple trials, reliable source

Question 8

What does it mean to be biased?

Answer 8

It is having an opinion and trying to sneak it into talking or writing, presenting information that proves your point and concealing information that contradicts it. You’re trying to hide your opinion and trying to appear as a reliable source of information.

Question 9

What is the difference between science and engineering?

Answer 9

Science is trying to find the relationship between two variables. Engineering is trying to manipulate variables for a desired income.

Question 10

What does an engineering question look like?

Answer 10

How can we change ________ to get ______(desired outcome)?

Question 11

What is a scientific model? What are two things that it does?

Answer 11

A scientific model is something that represents an aspect of our universe. It pictures: shows an aspect of our universe, and predicts: predicts what will happen in the future, or in a certain situation.

Question 12

What is the difference between a physical model and an abstract model?

Answer 12

A physical model is something that you can see, touch, and manipulate. An abstract model is something in your head, like an analogy, that helps you to picture something. (ex. the sun is a ball of fire)

Question 13

Is a model ever correct?

Answer 13

A model can never be correct because we will never know everything. We are always discovering more about the world around us that God has created. We will never be able to understand everything.

Question 14

What are the five key parts of a science experiment?

Answer 14

1. Source
2. Incoming Objects
3. Target
4. Outgoing Objects
5. Detector

Question 15

What is the structure of an atom?

Answer 15

The nucleus (center) includes the neutrons (neutral) and protons (positive). The electrons (negative) orbit around the nucleus.

Question 16

Why was Rutherford’s experiment a scattering experiment? What are the five parts to his experiment?

Answer 16

Source: radioactive rock
Incoming Object: the alpha particles
Target: the atoms of the thin gold leaf
Outgoing Objects: the alpha particles
Detector: a screen that flashed when hit, eyes
His experiment was a scattering experiment because it had these five pieces to the experiment. He had a source that shot radioactive particles at a gold leaf sheet. Some pieces went through and some bounced back. A detector was placed in different locations to see where the particles were going.

Question 17

What did Rutherford’s experiment teach us about the atom?

Answer 17

It taught us that the atom has some positive charge, packed tightly in the nucleus. It also taught us that the atom is mostly empty space, as only about 1 in every 8,000 particles bounced back.

Question 18

Choose a model of the moon’s creation and answer:
- What does this model do well?
- What does this model not do well?
- How does this fit with our idea of how science works?

Answer 18

The Accretion model:
- This really could have happened! There was a lot of debris around the earth, so it easily could have formed something the size of the moon.
- This model does not explain how the earth and the moon have slightly different compositions. The earth’s core is iron, while the moon’s is not.
-This fits with our idea about how science works because we do not know everything. We know that all of our models are flawed and always will require more knowledge and learning to perfect them. We know our models will never be perfect.

Question 19

What is the model of tectonic plates?

Answer 19

Our model is continental drift. This is the idea that all of the continental plates started off in one continent called Pangea. Over time the split apart and spread so that we eventually got the continents that we have today.

Question 20

What geologic evidence to we have to prove this method? (continental drift)

Answer 20

• rock formations across continents
• animal fossils found across continents
• the shapes of the continents
• similar fern fossils in very different climates
• coal in Antarctica

Question 21

Be able to draw in where tectonic plates are located based on volcanos or earthquakes.

Answer 21

Basically-volcanos and earthquakes largely occur on the edges of plates.

Question 22

Based on our knowledge of continental drift, why is it safe to say there will be a major earthquake someday in California?

Answer 22

California is at a transform plate boundary. This means that the plates are scraping alongside each other. This means there will be earthquakes. There is a lot of pressure and friction as they grind alongside each other.

Question 23

Where would you expect to find older fossils and rocks: on the floor of the Atlantic Ocean, or on the continental United States? Why?

Answer 23

You could expect to find older fossils on the continental United States because it is older. According to the Continental Drift theory, when Pangea existed, the Atlantic did not exist. As it spread out, the Atlantic formed between the plates. The Atlantic floor has a divergent boundary, and it is always getting baby rocks. This means a lot of the ocean floor is newer.

Question 24

Be able to label the layers of the earth on a model. List them in order and describe them.

Answer 24

1. Inner Core: solid mostly iron
2. Outer Core: a liquid layer around the core responsible for our magnetic field
3. Mantle: 70% of earth’s volume, somewhat fluid, allows heat transfer from the middle of the earth to the outside
4. Asthenosphere: plastic-like layer under the solid part of the mantle
5. Lithosphere: outer layer of the earth, containing the crust and upper mantle
6. Crust: thin, outermost layer of the earth

Question 25

Which layer is the most dense? Which layer is the least dense? What is your reasoning for that claim?

Answer 25

The most dense is the inner core. This is because it is at the center and will have the pressure of all of the other layers on it. The least dense is the crust, because it does not have all of the pressure of so many layers on it.

Question 26

How do they use seismic activity data to support the idea of an inner core and an outer core?

Answer 26

They sent seismic waves through the earth. At a certain point in the core, the waves’ velocity changed drastically. This proved that there were two different layers to the core.

Question 27

How do you make two liquids of the same substance that have different densities? What does this have to do with hot things rising and cold things sinking?

Answer 27

You must make the liquids different temperatures. This is because temperature affects density. Hot liquids are less dense. They will rise to the top. Cool liquids are more dense and will sink.

Question 28

What is convection? What causes it? How does it work?

Answer 28

Convection is caused by differences in density. It is the movement of substance. The less dense substance will rise, and the more dense substance will sink. If it is with temperature, as the hot water cools and sinks, and as the cool water warms, it rises, forming a convection current.

Question 29

What is the driving force of plate tectonics? (be able to draw it)

Answer 29

Convection currents in the earth’s mantle (magma).

Question 30

Why does the earth seem to have two levels?

Answer 30

The oceanic plates are more dense, and will sink. The continental plates are less dense and will not sink.

Question 31

Name and describe the three main categories of plate boundaries

Answer 31

Divergent: the plates are moving apart
Convergent: the plates are moving together
Transform: the plants are moving side by side

Question 32

What type of geologic features indicate a convergent boundary on land or in the ocean? Where would you find an example of these boundaries?

Answer 32

Land/Land: Mountains
Land/Ocean: Volcanos
Ocean/Ocean: ocean trench, volcanos

Question 33

What type of geologic features indicate a divergent boundary on land or in the ocean? Where would you find an example of these boundaries? Be able to draw a picture of all plate boundaries.

Answer 33

Land/Land: ocean forms between continents
Ocean/Ocean: mid-ocean ridges, rock babies.

Question 34

What is weathering? What are some causes of weathering?

Answer 34

Weathering is the breaking down of objects into smaller pieces (like rocks). Weathering can be caused by precipitation, earthquakes, wind, etc.

Question 35

What is erosion? What are some causes of erosion?

Answer 35

Erosion is the movement of pieces broken down by weathering. Erosion can be caused by wind, water, gravity, and more.

Question 36

What is happening to the Islands of Hawaii?

Answer 36

The islands of Hawaii are over a hot spot. As the plate shifts, the hot spot is over a different area and will form a new piece of land with the magma coming up. As islands get farther away from the hotspot, they weather and erode, and eventually fall to the ocean floor.

Question 37

How does the trail of Hawaiian islands support the model of tectonic plates in motion?

Answer 37

It supports it because if the plate stayed in one spot, there would always be one continuous island. Since the islands form and erode over the years, it proves that they are moving since the hot spot does not move. We can even see that the tectonic plate’s direction must have changed at some point.

Question 38

How do fossils help determine the age of the rock it was found in?

Answer 38

Based on what is in the fossil, we can look at the year that that specimen was around. We know that the rock must be younger than that to have formed around the specimen.

Question 39

How do older layers sometimes end up above younger rock layers in a folded mountain range?

Answer 39

The mountain is pushed together because of the motion of the tectonic plates. Eventually the younger layers can fold under and the younger layers can fold over.

Question 40

What is the principle of superposition?

Answer 40

That as rock layers form, the oldest layer will be at the bottom and the youngest at the top.

Question 41

What is the principle of uniformitarianism?

Answer 41

That all rocks have been formed the same way throughout time.

Question 42

*Do the rock layer diagram on 2.4

Answer 42

:)

Question 43

The half-life of an unknown substance is 25 years. If you found it when it still had 12.5% left
a. How many half lives have passed?
b. How old is that substance?

Answer 43

a. 3 half lives
b. 75 years old

Question 44

If 160 grams of Ag-105 decays to 5 grams in 206.45 days, what is the half-life of Ag-105?

Answer 44

The half-life is 41.29

Question 45

The half-life of radon-222 is 3.8 days. If 50 grams are left after 19 days, how many grams were in the original sample?

Answer 45

1600 grams

Question 46

The half-life of I-137 is 8.07 days. If 2.5 grams are left after 56.49 days, how many grams were in the original sample?

Answer 46

320 grams

Question 47

*do more half life graph practice

Question 48

What lessons about creation did we discuss and learn about from the example of the wolves being reintroduced to Yellowstone? How does this relate to Psalm 8?

Answer 48

-We talked about how one small thing can make a tremendous change on an ecosystem. Introducing the wolves brought back some balance to the ecosystem of Yellowstone.
-This relates to Psalm 8 because we are the keepers of creation. We need to take care of it properly, and not waste it. We have been made a little lower than the angels to take care of earth. We need to take care of the smallest pieces to save the earth, rather than take it for granted.

Question 49

What is the difference between climate and weather?

Answer 49

Climate is the average atmospheric conditions for a location. Weather is the day to day conditions that occur.

Question 50

What different factors do we include in the concept of weather?

Answer 50

Temperature, cloud cover, precipitation, dew point, humidity, etc.

Question 51

*be able to replicate the convection map we made

Answer 51

:)

Question 52

Know the names, locations, and directions of the convective cells in the atmosphere. (Be able to recreate them by drawing a picture of it or labeling a picture)

Answer 52

Polar (pole, clockwise)
Ferrel (middle, counterclockwise)
Hadley (equator, clockwise)

Question 53

What is the coriolis effect? What are a couple of things we see happen to our weather system because of this effect?

Answer 53

It is the deflection of moving objects because of the earth’s rotation. Some things that occur are the convection cycles!

Question 54

What is the difference between a high pressure and a low pressure system? Which one will give you more clouds? Why is that?

Answer 54

A high pressure system pushes down and has lots of pressure. It will be very humid. A low pressure system pushes up, and more clouds will form because the air is allowed to cool and condense.

Question 55

What are the two short scale (1-5 year) climate variations we learned about in 3.2?

Answer 55

El Niño and volcanic sulfur in the atmosphere.

Question 56

Over the short term, how do volcanoes end up making the earth’s climate colder?

Answer 56

The volcanic sulfur mixes with the atmosphere. This causes solar radiation to reflect rather than go through. This makes it colder.

Question 57

What is a positive feedback loop? What is a negative feedback loop?

Answer 57

Positive: changes are amplified!
Negative: both factors even each other out

Question 58

What is an example of a positive feedback loop? What about an example we might see in climate/weather?

Answer 58

• flowers die. The ground is fertilized by this, paving the way for more flowers to grow. As they die, more soil is fertilized, so more flowers grow!
• There is a lot of albedo as the sun is reflected off of the ice. As the ice melts, the albedo lowers, causing more warmth to be absorbed in the water, causing more ice to melt.

Question 59

What is an example of a negative feedback loop? What about an example we might see in climate/weather?

Answer 59

• This is what happened in yellowstone. Wolves eat rabbits, so the rabbits die out, causing the wolves to have no food and they die out, causing the rabbit population to grow, causing the wolves to have more food again.
• sunlight reflects off of the surface of water, causing the water to evaporate and form a (specific kind) of cloud. As the clouds cover the sun, the water cools and no longer evaporates, causing the clouds to leave and the sun to come back out.

Question 60

What is happening in the Pacific ocean in an El Niño year? What kind of feedback loop is this? Why do you think that is? Make sure you can draw it out.

Answer 60

Positive feedback loop. The pacific water warms, causing the water to evaporate and causing a wind. The wind increases, pushing the warm water together and causing more water to evaporate!

Question 61

What happens to the sun’s energy output over time? How does this variability affect the climate over a timescale of 100 years?

Answer 61

The sun’s energy output increases and decreases over time. This will change a climate slightly over 100 years.

Question 62

What is meant by the term “greenhouse gas”?

Answer 62

A greenhouse gas are the gases in the atmosphere that reflect heat back toward earth.

Question 63

Are greenhouse gases good or bad for our climate?

Answer 63

Greenhouse gases are good for our climate because without them, we’d be a frozen ball of ice. They trap in the heat to keep us warm. One bad thing, however, is that too many gases are being trapped in he atmosphere, meaning that too much heat is being reflected back. This is global warming.

Question 64

When does the carbon dioxide in our atmosphere seem to be at its lowest levels in the northern hemisphere? Why might that be?

Answer 64

It seems to be at the lowest levels when we have summer. This is because this is the time when plants are absorbing carbon dioxide to use in their photosynthesis processes. Also there will be more alive plants during this time. They suck up the carbon dioxide, but give out only oxygen!

Question 65

Where does most of the carbon dioxide appear to be coming from, the northern or southern hemisphere? Why is that the case?

Answer 65

The most carbon dioxide comes from the Northern hemisphere. This is because more people live there. In fact, about 90% of the earth’s population lives in the northern hemisphere. More people are going to use more energy and cause more emissions to occur.

Question 66

Describe and explain one method of carbon capture that we discussed in class

Answer 66

One method of carbon capture is planting trees. This works because the plants are sucking up the carbon dioxide to use for their natural photosynthesis processes. The plants do not give out any carbon dioxide, but only oxygen! This process alone, however, cannot prevent global warming. It will do some good work, but not enough. The best thing to do would be to use this process along with others.

Question 67

What does the term Albedo mean?

Answer 67

Albedo is the percentage of incoming sunlight that is reflected rather than absorbed in a substance.

Question 68

How does the change from ice to water change the albedo of the earth? What type of feedback loop is this?

Answer 68

This lowers the albedo of the earth because ice is more reflective than water. This is a positive feedback loop because as the albedo lowers, more solar energy is absorbed into the water, causing the water to warm and more ice to melt.

Question 69

How do you think the amount of asphalt in big cities affects the temperature of the area? How does this relate to a city’s albedo?

Answer 69

Asphalt in cities is going to increase the temperature. This relates to albedo because asphalt has a very low albedo. Lots of the sun’s power is absorbed rather than reflected, meaning that the asphalt warms, causing the city to warm.

Question 70

Why does ocean water sink in the Polar Regions? Give two reasons.

Answer 70

Ocean water sinks in Polar Regions for two reasons. First, because there is a lot of salinity there. Second, because the water is very cold. Being cold and very salty are both ways that make water dense, meaning that here, the water will be very dense. This means that it will sink.

Question 71

Why is the circulation of ocean water masses called “thermohaline circulation”?

Answer 71

Thermo-meaning temperature, and haline-meaning salinity, are both extremely important factors that cause the water to circulate. This is because it causes different densities to occur, so the water moves and changes as such.

Question 72

What ocean movements does the thermohaline circulation not explain?

Answer 72

It does not explain the tides, waves, or El Niño

Question 73

What predictions can we make about how the earth’s climate might look if the ocean currents slowed down or even stopped all together? Try to come up with a few different examples of what we might see happen to different areas around the globe.

Answer 73

• Europe would get cold because the warm water would no longer circulate there.
  -Polar regions would get colder because the cold water would stay there.
  -locations near the equator would get warmer because the warm water would not circulate away.

Question 74

Be able to name, draw and explain the three types of Earth orbital movements (called Milankovitch cycles)

Answer 74

Wobble: The tilt of the earth changes in comparison to its orbital plane in about 26,000 year cycles.
Tilt: The tilt of the earth changes in about 41,000 year cycles.
Orbit: over about 100,000 year cycles, the earth’s orbit around the sun changes from more circular to more oblong.
Over time these, together, change the earth’s climate by changing the amount of solar radiation that the earth receives. When it receives more, it will be warmer. When it receives less, it will be colder.

Question 75

*Use the graphs to look at the stars and decide which elements are in them!

Question 76

What is the ocular lens?

Answer 76

The piece that you look through

Question 77

What is the nosepiece?

Answer 77

The piece that houses the objective lenses.

Question 78

What are the objective lenses?

Answer 78

magnify the specimen

Question 79

What are the stage clips?

Answer 79

hold down the specimen

Question 80

What is the stage?

Answer 80

Holds the specimen

Question 81

What is the coarse adjustment knob?

Answer 81

Adjusts how close the objective lenses are to the specimen.

Question 82

What is the diaphragm?

Answer 82

Controls the amount of light reaching the specimen.

Question 83

What is the light source?

Answer 83

Provides light to the specimen.

Question 84

What is the fine adjustment knob?

Answer 84

Brings in the fine details.

Question 85

You have a microscope that is on low power (it’s field of view is .450 mm across.) You measure the object to appear 3cm long and the field of view to be 5 cm wide. How big is your object actually?

Answer 85

0.27 mm

Question 86

A cell is 1 cm long. The FOV is 4.9 cm. Assume that the microscope is on high power.
[High power has 43x magnification and it’s field of view is 0.105 mm wide.]

Answer 86

(about) 0.0215 mm