STAAR Test

Some students in a chemistry lab conducted an investigation in which they added four different solid substance to separate beakers of water. They stirred the mixtures for one minute and then recorded their observations in the table below. Which substance most likely caused a new substance to be formed when mixed with water?

• substance 1

• substance 2

• substance 3

• substance 4

Tags

NGSS.MS-PS1-2

A teacher asks a student to write the chemical equation for photosynthesis. The student's response is shown. The equation is not balanced correctly. Which of these is a balanced equation for photosynthesis?

• 12CO₂ + H₂O ------> C₆H₁₂O₆ + O₂

• CO₂ + 9H₂O ------> C₆H₁₂O₆ + O₂

• CO₂ + H₂O ------> 3C₆H₁₂O₆ + O₂

• 6CO₂ + 6H₂O ------> C₆H₁₂O₆ + 6O₂

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

Nitrogen dioxide is a gas that can be generated by emissions from vehicles and factories. It can also be generated by natural sources, such as forest fires, lightning, and microbial activity win soil. The equation for producing nitrogen dioxide is shown. Which of these provides evidence that a chemical reaction occurs?

• A gas is present

• The total number of atoms remains unchanged.

• The state of matter remains the same.

• A brown gas is produced.

Tags

NGSS.MS-PS1-2

An energy pyramid is shown. Which sentence best describes how energy flows through this pyramid?

• Energy is transferred down each level of the energy pyramid.

• The energy lost at each level is consumed by organisms in the top level.

• Energy is transferred from organisms in one level to those in the level above.

• The organisms at the bottom level provide energy directly to organisms in all the other levels.

Tags

NGSS.MS-LS2-3

The diagram shows two different forces acting on a cyclist riding a bicycle. The total mass of the cyclist and the bicycle is 100.0 kg. Based on this information, what is the acceleration of the cyclist?

• 0.66 m/s² backward, because the force of the air slows the cyclist down.

• 0.66 m/s² forward, because the applied force is greater than the force of the air.

• 2.3 m/s² backward, because the forces are opposite and not equal

• 2.3 m/s² forward, because the cyclist's inertia is greater than the force of the air.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A block is pulled 0.90 m to the right in 2.5 s. What is the block's average speed to the nearest hundredth of a m/s?

• 2.78 m/s

• 2.25 m/s

• 0.36 m/s

• 2.78 f/s

Tags

NGSS.MS-PS3-1

The model shows Earth in several positions relative to the Sun. In which position is it winter in North America?

• Position 1, because North America receives the most direct sun

• Position 2, because North America is tilted toward the sun

• Position 3, because North America is parallel to the sun

• Position 4, because North America is tilted away from the sun

Tags

NGSS.MS-ESS1-1

The topographic map shows the location of a park ranger at Point when a message is received that an injured hiker needs help at Point Z. Which of these is closest to the difference in elevation between the locations of the ranger and the injured hiker?

• 2,050 m

• 450 m

• 910 m

• 3,650 m

Quasars are extremely distant celestial bodies. Investigators using a special telescope determined that a certain quasar was emitting waves with a frequency of 1.41 x 10⁹ Hz. An electromagnetic spectrum is shown. The investigators were most likely using a telescope that detects...

• microwaves

• visible light

• x-rays

• gamma rays

Tags

NGSS.HS-PS4-1

A student models convection currents in a laboratory activity. How are the convection currents in the student's model different from the convection currents in Earth's atmosphere and oceans?

• The warm air in Earth's atmosphere and the warm water in Earth's oceans sink instead of rise.

• The heat source for Earth's atmosphere and oceans is the sun, which heats from above instead of below.

• Convection cells in Earth's atmosphere and oceans flow in the same direction instead of opposite directions.

• Cold air in Earth's atmosphere and cold water in Earth's oceans are less dense that warm air and warm water instead of being more dense.

Tags

NGSS.MS-ESS2-6