
A substance is found to be reactive, flammable, soluble, and explosive. Which of these observations is a physical property?
Holding a marshmallow near a campfire flame causes it to turn brown even if the marshmallow does not touch the flame. Why does this happen?
The substances in a chemical reaction that are combined or separated to form new substances are the _______.
Which of the following is an example of a compound?

A model of a carbon dioxide molecule is shown in the image to your left.
Which of the following best describes the carbon dioxide molecule?

In atomic theory, new substances are formed when the atoms of other substances are rearranged. In this kind of change, the total number of atoms is conserved.
An example of this is shown in the diagram below. There are six atoms
both before and after the arrow.
Which statement below is also true of the rearrangement of atoms?