STAAR TEST 2019 GRADE 8 SCIENCE

The chart list organisms in five different categories living near the Texas Gulf Coast. Based on the chart, which food chain best models a flow of energy in this ecosystem?

• 
• 
• 
• 

A student makes a model of the sun-Earth system by swinging a ball around her head. Using this model, the student is trying to explain to how Earth stays on a path around the sun. The student explains that this path is the result of -

• F. the magnetic attraction between Earth and the sun

• G. potential energy stored in Earth that originated in the sun

• H. the gravitational attraction between the sun and Earth

• J. electromagnetic energy from the sun pulling on Earth

Atoms of which of two elements have a combined total of 23 protons?

• A. Sodium, Na, and magnesium, Mg

• B. Boron, B, and carbon, C

• C. Copper, Cu, and zinc, Zn

• D. None of these

The spectral classes of four stars are shown in comparison with a Hertzsprung-Russell diagram. Based on the information, which star is most like the sun?

• F. Star 1

• G. Star 2

• H. Star 3

• J. Star 4

Primary succession occurs when pioneer species move into an area that has no plants. Which organisms are common pioneer species?

• A. Conifer trees and tall grasses with roots that loosen the soil

• B. Mosses and lichens that can grow on rocky surfaces

• C. Grasses and weeds that arrive as seeds carried by the wind and then germinate in rich soil

• D. Vines and shrubs that help prevent the erosion of shallow soil

A mother and daughter press their hands together and then push apart while ice skating. Immediately after they push away from each other, how does the motion of the mother and daughter changed?

• F. The mother moves forward, and the daughter moves backward with a greater acceleration.

• G. Both move forward, but the mother moves with a greater acceleration.

• H. The mother moves backward, and the daughter moves forward with a greater acceleration.

• J. Both move backward, but the daughter moves with a greater acceleration.

A teacher asks students to make a model of a transform plate boundary. The students use blocks to represent tectonic plates and slide the blocks past each other in the directions of the arrows as shown. Which event can the students best demonstrate with their model?

• A. An earthquake

• B. volcanic eruption

• C. Formation of a rift valley

• D. Building up of a mountain

Which statement best describes evidence that a chemical reaction occurs as a cake bakes?

• F. The water in the cake batter evaporates.

• G. The cake rises as gas bubbles form in the baking cake.

• H. The cake takes the shape of the container in which it is baked.

• The water in the cake batter is used to keep the cake moist as it bakes.

A group of students used this diagram to classify three organisms into different kingdoms. Which table correctly identifies the three kingdoms?

• 
• 
• 
• 

A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which questions will best help the student classify the material?

• F. Is the material malleable or ductile?

• G. Does the material feel hard to the touch?

• H. Will the material float in water?

• J. Does the material feel rough or smooth?