CBA Review OL

Which of the following are considered pure substances? Select TWO correct answers.

• Element

• Compound

• Solution

• Homogeneous mixture

• Heterogeneous mixture

Beach sand is made of small, worn rocks and fragments of shells and sponges. This means that beach sand is —

• A solid

• A mixture

• A compound

• Unstable

Which is the BEST evidence that a chemical change has occurred?

• Change of state

• shape change

• cutting paper

• Formation of a new substance

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student added 10 mL of sodium chloride, NaCl, to 100 mL of water and then stirred the mixture until the salt was no longer visible. Which of the following BEST describes the mixture?

• Sodium chloride is the solute, water is the solvent, and salt water is the solution.

• Sodium chloride is the solute, salt water is the solvent, and water is the solution.

• Water is the solute, sodium chloride is the solvent, and salt water is the solution.

A student is given a sample of blue liquid. The student then adds an additional 250 milliliters of water to the solution and stirs. Which of the following best describes the solution after the water has been added?

• The solution becomes more diluted and will appear paler ( lighter) in color.

• The solution becomes more diluted and will appear darker in color.

• The solution becomes more concentrated and will appear paler (lighter) in color.

• The solution becomes more concentrated and will appear darker in color.

What happens to the rate of dissolution when you crush a sugar cube before adding it to water?

• The rate decreases

• The rate stays the same

• The sugar doesn't dissolve at all

• The rate increases

As temperature increases, what happens to the rate at which a solid solute dissolves?

• It decreases

• It stays the same

• It increases

• It fluctuates randomly

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Which of the following is true about distance?

• It is always equal to displacement

• It is the total path length traveled by an object

• It is always measured in a straight line

• It includes both speed and direction

Students performed multiple trials of a tennis ball rolling across the floor and recorded their observations. Select all of the trials with enough information to calculate the velocity of the tennis ball.

• Trial 1: rolled toward the left for 6 meters in 2 seconds before stopping

• Trial 2: rolled 12 meters in 5 seconds before stopping

• Trial 3: stopped after it rolled 4 meters in 2 seconds

• Trial 4: stopped after it rolled toward the right for 3 meters in 1 second

Tags

NGSS.MS-PS3-1

Jack placed a coin on a card on top of a glass. He quickly pushed the card and the coin fell into the cup. Which statement below best explains this result?

• Force is equal to mass times acceleration.

• A body in motion tends to stay in motion or a body at rest tends to stay at rest unless acted on by an outside force.

• Momentum equals mass times velocity.

• For every action there is an equal and opposite reaction.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2