Chapter 1, Problem 1.71EP

In the following diagram, the different colored spheres represent atoms of different elements. Four changes, denoted by the four numbered arrows, are shown.

Select the change, by listing the arrow number, that represents each of the listed situations. (Note that there may be more than one correct answer for a given situation and that answers may be used more than once or not at all.)

1. a. Which change(s) is a (are) physical change(s)?
2. b. Which change(s) is a (are) change(s) in which two elements combine to form a compound?