Question

part 2: physical vs. chemical properties
review notes

• physical properties can be observed without changing a substances chemical identity (color, density, melting point, solubility).
• chemical properties describe a substances ability to undergo changes that transform it into a different substance (flammability, reactivity with acid, ability to rust).

practice problems
decide whether each statement describes a physical property (p) or a chemical property (c):

1. gold is yellow and shiny.
2. iron reacts with oxygen to form rust.
3. water boils at 100°c.
4. baking soda reacts with vinegar to produce carbon dioxide gas.
5. sugar dissolves in water.
6. magnesium burns with a bright white flame.

part 3: reflection & application
answer in complete sentences:

1. why is it important for scientists to use significant figures when reporting measurements?
2. explain the difference between a physical change and a chemical change. give an example of each from your daily life.
3. which part of this assignment (sig figs or physical/chemical properties) do you feel more confident about now? which part do you still need more practice on?

Explanation:

Step1: Recall physical property definition

Physical properties can be observed without changing chemical identity.

Step2: Analyze statement 1

Gold's color and shininess can be observed without chemical change, so it's a physical property (P).

Step3: Analyze statement 2

Iron reacting with oxygen to form rust is a chemical change, so it's a chemical property (C).

Step4: Analyze statement 3

Water boiling at 100°C is a phase - change without chemical change, so it's a physical property (P).

Step5: Analyze statement 4

Baking soda reacting with vinegar to produce carbon dioxide is a chemical change, so it's a chemical property (C).

Step6: Analyze statement 5

Sugar dissolving in water is a physical change (no new substance formed), so it's a physical property (P).

Step7: Analyze statement 6

Magnesium burning is a chemical reaction, so it's a chemical property (C).

Answer:

1. P. Gold is yellow and shiny.
2. C. Iron reacts with oxygen to form rust.
3. P. Water boils at 100°C.
4. C. Baking soda reacts with vinegar to produce carbon dioxide gas.
5. P. Sugar dissolves in water.
6. C. Magnesium burns with a bright white flame.