Chemistry Homework 6/19/13

1. Physical properties are properties that can be observed and measured without changing the chemical makeup of the substance. 


2. Physical properties of water are density, freezing point of water, boiling point, and melting point. 

3. Solid water is much less dense than liquid water. That's why ice floats to the top, when placed in liquid water. 

4. You might observe water as a solid, liquid, and a gas at the same time when you are by a lake. The lake would have liquid water, the top of the lake would be frozen as a solid, and when water is put on the frozen lake, gas would rise up. 

5. A heterogeneous mixture is a mixture that is not the same or uniform throughout. A homogeneous mixture is the opposite; it is a mixture that is uniform throughout and evenly distributed. 

6. You need to know how dense each substance is, in order to predict which liquid will be on the top of bottom. The less dense substance will be on the top. 

7. 

a. a suspension

b. a suspension 

c. a colloid

d. a solution 

e. a suspension 

f. a colloid 

8. Just like the Tyndall Effect, the beam of light passing into a darkened room through the blinds on a window reflects that since the light shines all the way through the room, it shows that there are small particles present in the air. This means that the air in the room is a collid; these particles are too small to come out through a filter. 

9. See drawing. 

10. This mixture is a colloid because just like the Tyndall effect, the beam of light passes through the mixture. Since no particles settle to the bottom, it cannot be a suspension. 

11. Substance has a uniform and definite composition, as well as distinct properties. Two examples are elements and compounds.

12. 

a. compound

b. element

c. compound

d. element 

e. compound 

f.. compound

g. compound