Chemistry

Experiment 1 Chemical and Physical Changes in Matter

100

What remains after heating the salt (NaCl) solution and evaporating the water?

Salt (NaCl) crystals

200

A chemical change always results in:

A new substance being formed

300

Burning a substance is an example of a _________ because new substances are formed.

chemical change

400

When copper(II) nitrate (Cu(NO₃)₂) is heated, toxic gases are released. What precaution should be taken?

Perform the experiment in a well-ventilated area

500

Which of the following is NOT a sign of a chemical change?

Change in state (solid to liquid)

Experiment 2 Determining the Density of Liquids

100

Which formula is used to calculate the density of a liquid?

Mass ÷ Volume

200

Why is the tare function used before adding the liquid?

To reset the balance to zero

300

Which of the following liquids is expected to have the highest density?

Pancake syrup

400

Which liquid is typically the least dense?

Ethanol

500

If a liquid _______ on another, it has a lower density.

floats

Experiment 3 Does Temperature Affect the Density of Liquids?

100

Which tool is used to monitor liquid temperature?

Thermometer

200

Which temperature is not listed in the experiment's procedure?

50°C

300

What usually happens to a liquid’s density when it's heated?

It decreases

400

Cooling a liquid increases its ________.

Density

500

Why is volume measured at different temperatures in this experiment?

To understand temperature effects on density

Experiment 4 Determining the Density of Solids (Rocks)

100

Which method is used to find the volume of a rock?

Water displacement

200

How is volume determined in the water displacement method?

By subtracting final and initial water volumes

300

A possible source of error in this experiment is _________.

air bubbles

400

If a rock floats in water, its density is:

Less than 1 g/mL

500

What unit is used for recording rock density?

g/mL

True or False

100

Dissolving salt (NaCl) in water is a reversible physical change.

True

200

Large rocks always have a higher density than small rocks.

False – Density is independent of size.

300

A precipitate form when two solutions chemically react to form an insoluble solid.

True

400

Oil and water mix easily because they have similar densities.

False – They do not mix because they have different polarities and densities.

500

As temperature increases, molecules in a liquid slow down and compress together.

False – They move faster and spread apart.