Mission Possible Day 21

SC.8. N.1.1

An investigation was designed to determine the effect of ultraviolet light on how mold grows. Two groups of mold were grown under identical conditions, except one group was only grown under ultraviolet light, while the other group was grown in total darkness. What is the group of mold grown without receiving any ultraviolet light?

• control

• hypothesis

• dependent variable

• limiting factor

SC.8. N.1.1

An experiment was carried out to answer the question “Does the ph of water affect the growth of radish plants?” Two groups of ten radish plants were set up. One group was watered with water having a ph of 3.0, and the other group watered with water having a pH of 7.0. Both groups of plants received the same amount of light, the same amount of water, and grown in the same type of soil. The heights of the plants were measured every 2 days for a period of 2 weeks. What was the outcome variable (dependent variable) in this experiment?

• heights of the plants

• pH of the water

• temperature of the water

• type of soil

SC.8. N.1.1

The bar graph below shows the height of a plant at the end of each week of five-week growth period.

Which statement represents a valid conclusion-based on the information in the graph?

• The plant was given water during the first three weeks, only.

• The plant will grow faster during the sixth week than it did during the fifth week.

• The plant grew fastest during the first three weeks, and then it grew slower.

• The plant grew slowest during the first three weeks, and then it grew faster.

SC.8. E.5.3

According to the Law of Universal Gravitation, the strength of gravitational attraction between two bodies in our solar system or elsewhere in space depends on two factors and their relationship to each other. Which two of the factors listed are involved in determining the force of gravity between two bodies in space?

• speed and mass

• time and motion

• mass and distance

• distance and speed

SC. 8.E.5.5

Astronomers discovered a number of stars in a distant galaxy. Some were red, others white, and still others yellow. They compared them with the information in the graph.

Which type of comparison were they able to make based on the information in the graph?

• White stars were larger than red stars.

• Red stars had lower temperatures than white stars.

• White stars were brighter than red stars.

• Red stars closer than white stars.

SC.8. E.5.9

The water levels at ocean beaches and in harbors rise and fall in regular cycles called high and low tides. The Moon is the main cause of high tides. Low tides occur between high tides. Which statement best explains how the Moon causes tides?

• A full Moon causes high tides, a new Moon causes low tides and other phases of Moon cause tides that rise and fall.

• The force of the Moon’s gravity pulls ocean water along a beach or harbor up into a high tide for a few hours and then lets it drop to low tide.

• The pull of the Moon’s gravity causes ocean water to bulge out, and the tidal bulge moves around the world as the Earth rotates and the Moon orbits Earth.

• When the Moon is over an ocean beach or harbor at night, the tide in that place forms a high tide and it forms a low tide when the Moon is not visible during the day.

SC.7. E.6.2

The labeled arrows show the processes rocks go through as they change from one form to another.

Which of the statements accurately describes some of the changes that can occur to igneous rock?

• Igneous rock can melt into magma and then cool forming metamorphic rock, which under heat and pressure forms sedimentary rock.

• When weathered and eroded, igneous rock can form sediments, which become sedimentary rock through heating and compaction or metamorphic rock through cooling and pressure.

• Igneous rock can form metamorphic rock through weathering and erosion creating sediments that when compacted and compressed form sedimentary rock.

• Heat and pressure can cause igneous rock to form metamorphic rock, which when they reach the surface can be weathered and eroded to form sediments that are compacted and cemented to form sedimentary rock.

SC.8. P.9.2

Your family is driving to Florida for spring break. As you are moving, the car burns gasoline in the engine. How is energy being transferred in the car’s engine?

• Electrical energy into thermal energy

• Mechanical energy into kinetic energy

• Chemical energy into mechanical energy

• Kinetic energy into potential energy

SC.8. P.9.2

Matter can go through two types of changes: physical changes and chemical changes. Chemical changes result in new substances, while physical changes do not. Which process is an example of a physical change?

• paper burning into ash

• dough being baked into bread

• apple juice turning into vinegar

• rock being crushed into gravel

SC.8. P.8.5

The figure below illustrates a chemical process between hydrogen (H) and oxygen (O).

What chemical process does the figure best illustrate?

• Elements breaking apart into atoms.

• Atoms of two different elements combining to form a compound.

• Two elements combining to form one new element.

• Two compounds combining to form a new compound.