a. Dalton and Macie determine that a chemical reaction must have taken place. When this kind of change takes place, atoms must be rearranged to form new substances.
Question 2
b. The evidence that was useful to Dalton and Macie includes:
- A new gas was formed.
- One of the substances formed had a new property.
The evidence that was not observed or was not useful includes:
- A solid dissolved in a liquid.
- They saw a new color.