Grade 8 Science CRUNCH TIME #2

Throughout history, scientific knowledge has changed. Which of the following resulted in an important change in scientific knowledge?

• the observation of phase changes of the Moon

• the discovery of the function of the DNA molecule

• the development of a hypothesis describing possible life on Mars

• the prediction of when a comet would be most clearly visible from Earth

Tags

NGSS.MS-ESS1-1

Cassandra flashes a beam of white light toward a prism. The prism separates the white light into different colors. Which of the following causes the separation of the white light?

• The white light is concentrated.

• The white light is absorbed.

• The white light is refracted.

• The white light is reflected.

Tags

NGSS.MS-PS4-2

Ms. Brooks demonstrated phase changes to her class. She lit a candle and let the melting wax drop into a beaker of cold water, as shown below. The temperature of the water was four degrees Celsius (4°C). Which statement best explains what happened to the wax as it came in contact with the cold water in the beaker?

• A. The wax changed from a liquid to a solid as it gave off heat to its surroundings.

• B. The wax changed from a liquid to a solid as it increased in temperature.

• C. The wax remained in the liquid phase as it decreased in temperature.

• D. The wax remained in the liquid phase as it absorbed heat.

Tags

NGSS.MS-PS1-4

In 1980, a scientific journal published an article describing the observations that led to a hypothesis. The hypothesis stated that an asteroid striking Earth brought about the extinction of the dinosaurs. Which of the following would best provide support for a scientific hypothesis?

• opinions and personal beliefs

• new evidence and personal opinions

• new evidence and additional observations

• additional observations and informed predictions

Tags

NGSS.MS-LS4-1

A student claims that studying rock layers on the side of a mountain would show that Earth has changed over geologic time. Which type of evidence from the rock layers best supports this claim?

• Some rock layers are solid, and other rock layers have holes that store water.

• Rock layers that are composed of sand and silt are found in different locations.

• Rock layers that are thick and smooth are deeper than rock layers that are thin and rough.

• Some rock layers contain fossils of plants, and other rock layers contain fossils of marine animals.

Tags

NGSS.MS-ESS1-4

NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

NGSS.MS-LS4-1

Nyles used a microscope to observe two different types of cells. Drawings of the two cells are shown below. (Refer to the diagram of two cells with parts labeled X and Y.) Which of the following best contrasts the functions of the cell parts labeled X and Y?

• A) Part X stores water for future use, whereas part Y releases water out of the cell.

• B) Part X holds the structures in place in the cell, whereas part Y keeps all molecules from leaving the cell.

• C) Part X provides energy for the cell, whereas part Y helps with photosynthesis in the presence of sunlight.

• D) Part X regulates substances that enter or exit the cell, whereas part Y provides protection and support to the cell.

Tags

NGSS.MS-LS1-1

NGSS.MS-LS1-2

The planet Saturn takes 10,747 Earth days to complete one orbit around the Sun. Why does Saturn take longer to complete one orbit around the Sun than Earth does?

• Saturn has stronger gravity.

• Saturn is farther from the Sun.

• Saturn has a thicker atmosphere.

• Saturn is the only planet with rings.

Tags

NGSS.MS-ESS1-3

A group of students slowly poured 100 milliliters (mL) of vegetable oil, 100 mL of colored water, and 100 mL of corn syrup into a 500-mL beaker. The students observed the beaker after 5 minutes and recorded their observations in their science notebooks. Which of the following are the students most likely trying to compare?

• the volume of the liquids

• the density of the liquids

• the weight of the liquids

• the color of the liquids

A chemist observes a reaction between two substances in a closed container. Which of the following would most likely happen if the temperature is increased inside the container?

• The rate of the reaction would increase.

• The mass of each of the atoms would increase.

• The two substances would release nuclear energy.

• The two substances would not change into different compounds.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

According to the passage, what did scientists conclude about coyote and wild boar activity?

• It is not related to human population size

• It is related to the population size of humans

• Coyotes are only active during the day

• Wild boars are only active at night