Homework Blog 3

ISBS #1-12 p. 50

1. A physical property is a property that can be observed and measured without changing the chemical makeup of the substance.

2. Three physical properties of water are freezing point, density, and boiling point.

3. Solid water is less dense than liquid water.

4. When water is heated it turns to gas. When gas cools, it condenses and turns back into water. When water reaches its freezing point, it turns to ice.

5. A heterogeneous mixture is one that not uniform throughout, for example: foul water. A homogenous mixture is uniform, throughout, f0r example salt water.

6. When gasoline and water are poured into the same container and form two distinct layers, you need to know their densities in order to predict which liquid will be on top.

7. Solution, suspension, or colloid:

a. Medicine with instructions to "shake before use": suspension

b. Italian salad dressing: colloid

c. Mayonnaise: colloid

d. A cola soft drink: solution

e. Oil-based paint: suspension

f. Milk: colloid

8. Air would be a colloid because different air particles are spread throughout the room and the light will therefore go in all different directions.

10. The clear, red liquid would be a colloid because the light passes through the mixture, signifying tiny particles in the mixture that scatter the light.

11. The term substance means an element 1 or a compound 2 with a uniform composition, as well as very distinct properties. 

12. Element vs. compound:

a. CO: compound

b. Co: element

c. HCl: compound

d. Mg: element

e. NaHCO3: compound

f. NO: element

g. I2: element