Question

1. which of the following are considered heterogeneous mixtures: (a) __________ (b) ________ (c) __________

cereal
paint
salad dressing

1. any material consisting of only one type of atom is classified as what?

a compound
an element
a heterogeneous mixture
a homogeneous mixture

1. classify the following

gold (au)
granite rock
calcium carbonate (caco3)
air
flavored sports drink

Explanation:

1. For question 16: Heterogeneous mixtures have visibly distinct components that do not mix uniformly. Cereal has distinct solid pieces, paint (when not fully mixed or as a suspension) has separate phases, and salad dressing separates into oil and aqueous layers, so all are heterogeneous.
2. For question 17: An element is defined as a pure substance made up of only one type of atom, which matches the question's description.
3. For question 18:

• Gold (Au) is a single type of atom, so it is an element.
• Granite rock has distinct mineral components that are not uniformly mixed, so it is a heterogeneous mixture.
• Calcium carbonate ($CaCO_3$) is a pure substance made of multiple bonded elements, so it is a compound.
• Air is a uniformly mixed combination of gases, so it is a homogeneous mixture (solution).
• A flavored sports drink has dissolved ingredients uniformly distributed, so it is a homogeneous mixture (solution).

Answer:

1. (a) cereal, (b) paint, (c) salad dressing
2. An element

18.

• gold (Au): Element
• granite rock: Heterogeneous mixture
• Calcium carbonate ($CaCO_3$): Compound
• air: Homogeneous mixture (solution)
• flavored sports drink: Homogeneous mixture (solution)