Question

vocabulary & key
pure substances & mixtures

1. which of the following qualifies as a pure substance? choose four correct answers.

a. element
b. compound
c. heterogeneous mixture
d. solution
e. any substance containing all identical molecules
f. any substance containing more than one type of molecule
g. water
h. milk

1. which of the following qualifies as a mixture? choose four correct answers.

a. element
b. compound
c. heterogeneous mixture
d. solution
e. any substance containing all identical molecules
f. any substance containing more than one type of molecule
g. water
h. milk

Explanation:

• Question 1:
• An element is a pure substance as it consists of only one type of atom.
• A compound is a pure substance formed by chemical combination of elements in a fixed ratio.
• Water (\(H_2O\)) is a compound (and thus a pure substance).
• Any substance with all - identical molecules is a pure substance (either an element or a compound).
• Question 2:
• A heterogeneous mixture has visibly different components.
• A solution is a homogeneous mixture (a type of mixture).
• Any substance with more than one type of molecule is a mixture.
• Milk is a colloid (a type of heterogeneous mixture).

Answer:

1. A. Element, B. Compound, E. Any substance containing all identical molecules, G. Water
2. C. Heterogeneous Mixture, D. Solution, F. Any substance containing more than one type of molecule, H. Milk