“Introduction to Chemistry”

What is Chemistry?

• Chemistry is the study of the composition of “matter” – (matter is anything with mass and occupies space), its composition, properties, and the changes it undergoes.

• Has a definite affect on everyday life - taste of foods, grades of gasoline, etc.

• Living and nonliving things are made of matter.

What is Chemistry?

Pure Chemistry Applied chemistry

Why Study Chemistry?• Everyone and everything around us

involves chemistry – explains our world• What in the world isn’t Chemistry?• Helps you make choices; helps make you a

better informed citizen• A possible career for your future• Used to attain a specific goal• What did we describe as “pure” and

“applied” chemistry?

Chemistry Far and Wide• Chemists design materials to fit

specific needs – velcro • perfume, paints, nonstick

cooking utensils, polyester fibers

• Two different ways to look at the world: macroscopic and microscopic

Chemistry Far and Wide• Energy – we constantly have greater

demands

Chemistry Far and Wide

• Medicine and Biotechnology-

Chemistry Far and Wide

• Agriculture

Chemistry Far and Wide• The Environment

Alchemy – developed the tools and techniques for working with chemicals

• The word chemistry comes from alchemy – practiced in China and India since 400 B.C.

• Alchemy has two sides:–Practical: techniques for working with

metals, glass, dyes, etc.–Mystical: concepts like perfection –

gold was a perfect metal

Lavoisier• In the late 1700s, Antoine

Lavoisier helped transform chemistry from a science of observation to the science of measurement – still used today

• He settled a long-standing debate about burning, which was…–Oxygen was required!

Steps in the Scientific Method1. Observations (uses your senses)

a) quantitative involves numbers = 95oFb) qualitative is word description = hot

2. Formulating hypotheses (ideas)- possible explanation for the observation, or “educated” guess

3. Performing experiments (the test)- gathers new information to help decide

whether the hypothesis is valid

Law vs. TheoryLaw vs. Theory

A A lawlaw summarizes summarizes whatwhat has has happened.happened.

A A theorytheory (model) is an attempt (model) is an attempt to explain to explain whywhy it happened – this it happened – this changes as new information is changes as new information is gathered.gathered.