Mara and Ivy are asked to identify two minerals in science class. To do this, they decide to study the physical properties of the minerals in the following ways.
1. Examine how they freeze.
2. Determine how they break.
3. Rub them on a white tile plate. What is the best method (or methods) for the girls to study the physical properties and
identity the two minerals?
1 only
2 only
1 and 2
2 and 3