8th Grade Science Semester Exam

The diagram models the forces acting on a box. What is the value of the horizontal Net Force acting on the box?

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NGSS.MS-PS2-1

NGSS.MS-PS2-2

A chemist added hydrochloric acid to a sample of baking soda in a beaker. Immediately, the mixture of the two chemicals began to fizz and bubble. Which of the following observations about the fizzing mixture provides evidence of a chemical reaction?

• The temperature of the beaker did not change.

• A substance escaped from the beaker in the form of a gas

• Some of the baking soda remained in the bottom of the beaker

• . Most of the baking soda appeared to dissolve in the acid

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following best describes the acceleration of an object?

• 30 m/s east

• 30 m/s

• 30 m east

• 30 m/s^2

The diagrams show forces acting on a toy car as it moves to the right. Which diagram shows the toy car that will most likely accelerate to the right based on these conditions?

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NGSS.MS-PS2-1

NGSS.MS-PS2-2

A mother and daughter press their hands together and then push apart while ice skating.

What is the net force on the mother and daughter as they push away from each other?

• 0 N

• 7500 N

• 750 N

• 30 N

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NGSS.MS-PS2-1

NGSS.MS-PS2-2

A demonstration helps students understand a principle of roller coaster design. Which answer choice correctly describes the ball's kinetic and potential energy?

• The ball has more potential energy at position X than position Z.

• The potential energy and kinetic energy of the ball are greatest at position Z.

• The ball has more kinetic energy at position Y than at position W.

• The potential energy and kinetic energy of the ball are equal at position X.

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NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-4

Serotonin is a chemical substance that acts as a neurotransmitter. It helps relay messages in the human brain. The formula for one molecule of serotonin is shown below. How many atoms in all are in a molecule of serotonin?

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NGSS.MS-PS1-1

The chemical formula for sodium sulfate is Na2SO4 . How many sulfur atoms are in the formula for sodium sulfate?

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NGSS.MS-PS1-1

Both the esophagus and the small intestine are involved in the digestion of food. The esophagus squeezes food into the stomach by wave-like muscle contractions. Peptidase enzymes in the small intestine break food molecules into smaller molecules. Which statement best describes changes to food during digestion?

• The muscle contractions result in chemical changes, while the action of the peptidase results in physical changes.

• The muscle contractions and the action of the peptidase both result only in physical changes

• The muscle contractions result in physical changes, while the action of the peptidase results in chemical changes.

• The muscle contractions and the action of the peptidase both result only in chemical changes.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which two elements on the periodic table are in the same period?

• Se and Te

• C and Sn

• F and Cl

• Mg and Ar