Dalton and Macie were conducting an experiment at school. During the experiment, they added a little dry yeast to some hydrogen peroxide. The combination began to bubble rapidly, and the container felt warm. They captured some of the gas that was formed, and they discovered that the gas they captured had a new property. When they put a lit match into the gas, it made the lit match glow much brighter!(2 points)

Question

a. Dalton and Macie determine that a
must have taken place. When this kind of change takes place, atoms must
.
Question 2
b. Which of the following pieces of evidence helped Dalton and Macie answer question a?(2 points)
evidence that was useful to Dalton and Macie evidence that was not observed or was not useful
A new gas was formed.

A solid dissolved in a liquid.

They saw a new color.

One of the substances formed had a new property.

Answer 1

Question 1:

a. Dalton and Macie determine that a chemical change must have taken place. When this kind of change takes place, atoms must rearrange to form new substances.

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Question 2:

b. Evidence that was useful to Dalton and Macie:

• A new gas was formed.
• One of the substances formed had a new property.

Evidence that was not observed or was not useful:

• A solid dissolved in a liquid.
• They saw a new color.

The useful evidence indicates a change in the composition of substances (new gas and new properties), while the other pieces of evidence do not directly indicate a chemical change related to their experiment.