Download science921key - Rocky View Schools

Topic 1 Review Answers
1. See Skill Focus 1 on Safety and WHMIS symbols
for answers.
2. Answers will vary, but should include the .re extinguisher,
.re blanket, eyewash station, .re exit, safety
goggles, aprons, broken glass container, acid and
base neutralizers, .rst-aid kit, etc.
3. In a pure substance, all particles in the substance
are identical. An example is the metal lead. A solution
contains at least two different types of particles:
the solvent particles (e.g., water) are more
numerous, and the solute particles (e.g., sugar) are
less numerous. The particles are very evenly mixed
together and cannot be seen with the naked eye. A
mechanical mixture consists of two or more types of
particles, not evenly mixed together.
4. (a) Soil is a mechanical mixture.
(b) Perfume is a solution.
(c) Baking powder might be expected to be a pure
substance (NaHCO3), but commercial baking
powders are generally a mixture of several ingredients.
(d) Glass cleaner is a solution.
5. Thinking Critically This is a good opportunity for
students to develop their concept of a solution
beyond the simple “solid in liquid” model they
already know. You might encourage students to
think about the particles in each of the examples
they suggest. Sample answers are suggested below,
although many others are possible.
TOPIC 2 CHANGES IN MATTER
Type of solute and solvent Examples
gas dissolved in a gas air
gas dissolved in a liquid carbonated beverage
liquid dissolved in a liquid radiator fluid
(water and antifreeze)