Science QA2 Review 2025-2026

A student placed a piece of silver metal into a jar with a dark green solution. The temperature of the solution was 35°C. The student made observations for 15 minutes.

Look at the picture and determine which observations provide evidence of chemical change?

• A. Observations 1 and 2

• B. Observations 3 and 4

• C. Observations 4 and 5

• D. Observations 2 and 5

A student dropped a solid blue cloth into a beaker with clear liquid that was 28°C and had a strong odor. See the student's before and after observations in the picture.

Which observation provides evidence that a new substance was formed in the beaker?

• The clear liquid has a strong odor.

• The solid blue cloth is now solid white.

• The temperature is 28°C.

• The liquid is clear.

A student conducted an investigation by combining two liquid reactants as seen in the picture.

After mixing the two liquid reactants together, a chemical change was observed.

Which of the following is evidence that a new substance was formed?

• The liquid reactants turned pink and were 10°C.

• The liquid reactants were swirling and had a weird smell.

• The liquid reactants took the shape of the container.

• The volume of the two liquid reactants increased and the temperature was 20°C.

See the before and after observations of a student who was observing a marshmallow as it was held over an open flame during a lab investigation.

Evidence that a chemical change has occurred is best shown by:

• A. Observations 2 and 4.

• B. Observations 1 and 2.

• C. Observations 2 and 3.

• D. Observation 2.

During a lab, students performed several investigation of two clear liquids with temperatures of 33°C. The two liquids were combined and observations were made. Which of the following observations most likely created a new substance? For each observation, indicate whether a new substance was created or not: 1. The solutions turned a hot pink and the temperature was 33°C. 2. Chunks formed and the temperature was 23°C. 3. The liquids remained clear and the temperature was 33°C. 4. One liquid floated on top of the other. 5. Gas bubbles were present and the temperature was 23°C.

• 1. New Substance Created 2. New Substance Created 3. No New Substance Created 4. No New Substance Created 5. New Substance Created

• 1. No New Substance Created 2. New Substance Created 3. New Substance Created 4. New Substance Created 5. No New Substance Created

• 1. New Substance Created 2. No New Substance Created 3. No New Substance Created 4. New Substance Created 5. No New Substance Created

• 1. No New Substance Created 2. No New Substance Created 3. No New Substance Created 4. No New Substance Created 5. No New Substance Created

What does the acronym PTCG stand for?

• P - Precipitate, T - Temperature Change, C - Color Change, G - Gas Bubbles

• P - Pressure, T - Time, C - Concentration, G - Gravity

• P - Photosynthesis, T - Transpiration, C - Chlorophyll, G - Growth

• P - Protein, T - Transport, C - Cell, G - Gene

What is the net force acting on the box and in which direction is the box moving?

• 12 Newtons to the left

• 12 Newtons to the right

• 36 Newtons to the left

• 0 Newtons, the box is stationary

A student observed three people pushing a car across a dirt road filled with mud. The net force acting on this car is 130N to the left. Which net force diagram accurately describes this situation?

• [Diagram A: 25N, 25N, 80N to the right]

• [Diagram B: 80N, 25N, 25N to the left]

• [Diagram C: 70N to the left, 30N, 30N to the right]

• [Diagram D: 50N, 50N, 50N to the left]

A toy airplane is flying with 200N of force. A huge gust of wind exerts a force of 800N against the airplane. Which description best describes the direction of motion for the airplane?

• The airplane will continue to move in the same direction.

• The airplane will come to a complete stop.

• The airplane will move in the direction of the wind.

• The airplane will stop and then move again.

A student conducted an investigation about balanced and unbalanced forces. The student hung mass weights from each spring and recorded the observations. Which mass and spring scale model represents a balanced force?

• Model A

• Model B

• Model C