DOL: 6.6E Evidence of Chemical Reactions (2)

Which of the following is an indicator of chemical change?

• Change in shape with the application of some type of force

• Change in temperature with no outside heat source applied

• The formation of a solid due to freezing

• The formation of a gas due to evaporation

Tags

NGSS.MS-PS1-2

The list shows what a student records when they observe a burning candle.

Which of the following observations of the burning candle indicate a chemical change?

• A. II and III, only

• B. I and III, only

• C. I and II, only

• D. I, II, and III

Tags

NGSS.MS-PS1-2

A student mixes baking soda and vinegar in a cup. They measure the temperature before and after mixing. Use the data table to answer the following question.

What does the temperature change tell us about what's happening in the cup?

• A. A chemical change is occurring, releasing more heat at higher starting temperatures.

• B. Only a physical change is happening, causing the temperature to rise.

• C. A chemical change is occurring, but it doesn't affect the temperature.

• D. The temperature rise is due to the room getting warmer, not the mixture.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Jake's class is learning about energy and chemical changes. Their teacher takes them to the school parking lot, where a car is parked. She explains that cars use a chemical reaction to produce energy for motion. The teacher starts the car and asks the students to observe carefully for 5 minutes. Jake notices:

-At first, the car engine makes a louder sound, then settles into a steady rumble.

-White smoke comes out of the exhaust pipe for a short time, then becomes invisible.

-After a few minutes, the hood of the car becomes warm to the touch.

-The windows of the car start to fog up slightly on the inside.

-A faint smell of gasoline can be detected near the car.

-The fuel gauge needle moves slightly toward empty.

The teacher asks the class: "Which of these observations provides the strongest evidence
that a chemical change producing heat energy is occurring in the car's engine?

• The change in the engine's sound from loud to a steady rumble.

• The fuel gauge needle moves slightly toward empty.

• The hood of the car becomes warm to the touch.

• The windows fogged up on the inside of the car.

Tags

NGSS.MS-PS1-2

Tom's class is studying energy transformations in rockets. The teacher provides the following information about rocket launches: - A bright, fiery exhaust comes out of the rocket's engines. - A loud roaring sound can be heard for miles. - A large cloud of steam forms around the launch pad. - The ground near the rocket appears blurry like hot air rising. - The rocket slowly lifts off and then accelerates quickly.

Which two observations are most important in understanding
what's happening in the rocket engines?

• A bright, fiery exhaust comes out of the rocket's engines.

• A loud roaring sound can be heard for miles.

• A large cloud of steam forms around the launch pad.

• The ground near the rocket appears blurry like hot air rising.

• The rocket slowly lifts off and then accelerates quickly.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

NGSS.MS-PS3-5