Question

You are building a shelf at home. As you sand the wood dust floats into the air. The air and dust from sanding create which of the following.

a. a solution
b. a pure substance
c. a colloid
d. a suspension

Answer 1

a colloid and a suspension are the same thing so it rules out c and d because the dust is heavier than air causing it to float down but not float constantly. a pure substance is one solid substance. so its be A. a solution. a solution is a homogenous mixture of 2 or more substances because it wouldn't only compose of wood dust because of the air oxygen and carbon dioxide keeping it from falling faster.

Answer 2

Solution, colloids and suspension are different kind of mixtures.

Air and dust are not solutions, because the dust can be observed (using light).

There is a doubt about whether air and dust form a colloid or a suspension.

Colloids do not separate, while suspension's components do separate. If the dust is small enough it will remain on the air long enough to be considered a colloid for all efects.

Then, the most acceptable opinion is that the mixture of air and dust is a colloid.

So, option c. a colloid.