Chemistry 101

What is Chemistry?

Chemistry is the study of matter, its properties, and how it changes. It is a physical science that involves analyzing substances on a molecular and atomic level.

States of Matter

Matter primarily exists in three states:

Solid
Fixed shape and volume

Liquid
Fixed volume, changes shape

Gas
No fixed volume or shape

Matter can change between these states through physical processes like melting, freezing, evaporation, and condensation.

Scientific Method

The scientific method is a systematic approach to acquiring knowledge. The key steps are:

1. Make an observation
2. Ask a question
3. Form a hypothesis
4. Conduct an experiment
5. Analyze results and draw conclusions
6. Report findings

Measurement and Units

Measurements in chemistry are quantitative observations. The metric system is used, with key units being:

• Mass - grams (g)
• Volume - liters (L)
• Length - meters (m)
• Temperature - degrees Celsius (°C)

Exercises

1. Describe a real world example of matter changing states.
2. What is the key difference between a solid and a liquid?
3. Outline the main steps of the scientific method.
4. Convert 250 mL to liters.