questions

1. A substance that is made up of only one type of atom is called a(n)_______________.
2. Two or more substances physically combined form a(n)______________.
3. Two or more substances chemically combined are called a(n)_______________.
4. Sand is a good example of a(n) ______________ mixture.
5. _______________ elements, such as oxygen (O2), are found in nature in their elemental form as two-atom molecules.



1. [element]

2. [mixture]—You might have said “solution, “homogeneous mixture,” or
“heterogeneous mixture,” which are also true answers. “Mixture” is the
most general of the possible correct answers.

3. [compound]—Remember: The key is that the elements in a compound are
chemically combined. If the question asked about things that are physically
combined, the answer would have been a “mixture.”

4. [heterogeneous]—Sand is composed of particles of different substances,
mixed together in a non-uniform distribution.

5. [diatomic]—“Diatomic” means “two-atom,” so think of O2 or H2 when you
see it.