Evidence of a Chemical Reaction

The picture shows an experiment in which a student mixed two clear liquids together.

The student can conclude that a chemical change occurred because...

• one substance was more dense than the other.

• there was no temperature change during the experiment.

• a solid formed when the two liquids were mixed.

• there was no change in mass during the experiment.

Tags

NGSS.MS-PS1-2

What is true about ALL chemical changes?

• They all produces gas/bubbles/fizzing

• They all have a temperature change (hotter/colder)

• They all change colors

• They all produce NEW and DIFFERENT substances

Tags

NGSS.MS-PS1-2

Which is NOT an indication of a chemical change?

• temperature change

• formation of a precipitate

• shape change

• production of light

Tags

NGSS.MS-PS1-2

When I go to Chipotle I love to order guacamole. It smells amazing and tastes even better! Unfortunately, sometimes I don't eat it fast enough and it turns brown. Stirring it up hides the brown, but if it sits out longer, it continues to change. What indicates a chemical reaction in this scenario?

• The guacamole smells amazing

• The guacamole tastes incredible

• The guacamole turns a yucky brown color

• I stir the guacamole to get rid of the brown

Tags

NGSS.MS-PS1-2

Milk Sours

• Chemical Change

• Physical Change

Tags

NGSS.MS-PS1-2

Which of the following examples shows that a chemical reaction has occurred? 

• A rock breaks into smaller pieces when it is struck with a hammer.

• Rust forms on a hammer that has been left outside to long. 

• A cup of water turns pink when a few drops of red food coloring are added. 

• A solid is formed when heat is removed from a sample of water. 

Tags

NGSS.MS-PS1-2

A student places a piece of a potato into a container of hydrogen peroxide. One observation the student makes is that bubbles form around the potato. The presence of bubbles might indicate the formation of a new substance because bubbles - 

• could show that a gas is forming

• always rise to the top of a liquid. 

• are almost always perfectly spherical.

• usually burst after a few minutes.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Four students performed four different investigations by combining different substances. Their results are shown in the table provided. In which experiment are new substances being formed?

• Experiment 1

• Experiment 2

• Experiment 3

• Experiment 4

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A clear liquid from a flask is poured into another clear liquid in a beaker. Which of the following results of this procedure would indicate a new substance was formed?

• The level of the substance in the beaker is higher after the other liquid is added.

• A yellow solid forms and then settles to the bottom of the beaker.

• Small white crystals are left behind in the flask that held the first liquid.

Tags

NGSS.MS-PS1-2

In a container, a solid consisting of clear crystals is combined with a blue liquid and the following observations are obtained.
 How many of the listed observations indicate a new substance was formed?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-2