Question

multiple choice write the letter that best answers the question or completes the statement on the line provided. 1. which of the following are pure substances? a. solutions b. compounds c. homogeneous mixtures d. colloids 2. a substance that is made up of only one kind of atom is a(an) a. compound. b. homogeneous mixture. c. element. d. solution. 3. what is the symbol for aluminum? a. al b. al c. au d. a 4. if a material contains three elements joined in a fixed proportion, it is a(an) a. mixture. b. solution. c. atom. d. compound. 5. which of the following is a mixture? a. carbon dioxide b. silicon c. silicon dioxide d. sand 6. a mixture that appears to contain only one substance is a(an) a. homogeneous mixture. b. heterogeneous mixture. c. compound. d. element. 7. a mixture can be classified as a solution, suspension, or colloid based on the a. number of particles it contains. b. size of its largest particles. c. color of its particles. d. size of its smallest particles. 8. which of the following is malleable? a. glass b. pottery c. ice d. gold 9. a substance has a melting point of 0°c and a boiling point of 100°c. the substance is most likely a. water. b. hydrogen. c. gold. d. table salt.

Explanation:

1. Compounds are pure substances as they have a definite composition. Solutions, homogeneous mixtures, and colloids are mixtures.
2. An element is made up of only one - kind of atom.
3. The chemical symbol for aluminum is Al.
4. A compound is made up of two or more elements joined in a fixed proportion.
5. Sand is a mixture as it contains various substances like silica, minerals etc. Carbon dioxide, silicon, and silicon dioxide are pure substances.
6. A homogeneous mixture appears to be a single - substance.
7. Mixtures are classified as solution, suspension, or colloid based on the size of their largest particles.
8. Gold is malleable. Glass, pottery, and ice are not malleable.
9. Water has a melting point of 0°C and a boiling point of 100°C at standard atmospheric pressure.

Answer:

1. b. compounds
2. c. element
3. b. Al
4. d. compound
5. d. sand
6. a. homogeneous mixture
7. b. size of its largest particles
8. d. gold
9. a. water