The scientific method

Revisited…one more time!

What is Chemistry?

It is the study of material sciences- matter, and the changes that they undergo.

Matter is anything that has mass and takes up volume.

Think-Pair-Share

What are some examples of things that you do that involve chemical processes or contact with chemicals?

What are some examples of things that you do that DO NOT involve chemical processes or contact with chemicals?

Skills necessary in ChemistryInvestigative Skill (Inquiry)-Problem posing-Problem solving-Analyzing and ConcludingScientific communication skills

How does one “do” science?Watch the following video segment and complete the corresponding notes.

Science in Action

Symbols in Chemistry!

This class is very much like learning another language…

Chemistry is about atoms

• And atoms are REALLY really really really really really really really really small. Really.

• This means we can’t see what they are doing individually.

• We have to make observations and gather evidence when things we can see or measure change.

ΔThis is the Greek letter Delta. In math and science, it means “change.”

Remember, atoms are really small…

• So we take measurements and make observations to try and explain chemically what we see happening.

• BUT, there are lots of chemists in the world…how are we all going to make sure we’re talking about the same things??

So we need a language!

• This language is made up of symbols (as is the English language).

• The symbols are a system we (as a community of Chemists) have agreed on to explain the information we are gathering.

• This way, everyone can understand each other!

Here’s your introduction to the language…

• There are 3 main symbolic systems we use in Chemistry.

• They are:– Words– Formulas– Diagrams

For example

• Words: When table salt dissolves in water, it separates into positive sodium and negative chloride ions.

• Formulas: NaCl(s) + H2O(l) Na+(aq) + Cl-(aq)

• Diagrams:

Each system is useful at different times

• (with your neighbor, decide what you think the MOST useful trait of each of the systems is)

• The Formulas system likely has the most new information in it, and predictably…that’s probably what we will spend most of our time talking about.

Different Uses

• Words– What we say out loud when we are talking about

Chemistry– Useful/helpful because words are familiar– You will need to learn some new words, and

precise science definitions for some familiar words

Different Uses

• Formulas– Convey A LOT of detailed information– There is lots to learn about the system – because

it is so full of detail.– This system revolves around the periodic table…it

is like a cheat sheet for much about this system.

Different Uses

• Diagrams– Helps to show how atoms are arranged in space

(at least the way we picture them)– Good for understanding the mechanism of how a

chemical reaction happens.– Used more heavily with covalent and organic

compounds.