When you come in, please get out your lab materials from yesterday. Do what you need to do to complete the lab (weigh sand) and complete the calculations. I will be collecting it in fifteen to twenty minutes. Finish up! If you are done, study for the quiz today.

Section 3.1-3.3

A measurement contains two things:1.Number2.Unit

The unit typically used in the sciences are those of the International System of Units.

Quantity SI base Unit Symbol

Length Meter m

Mass Kilogram kg

Temp Kelvin K

Time Second s

Amount of substance

Mole mol

Some number used in science are just too big to write out…For example: 1.There are a 602,000,000,000,000,000,000 hydrogen atoms in a gram of hydrogen.2.An atom of Au has a mass of 0.000000000000000000000327 gram

So what do we do?

A number in scientific notation is a product of two numbers:1.A coefficient (1≤X<10)2.10 raised to a power

Ex: 645,000Scientific notation: 6.45 X 105

This is the same as saying 6.45 X 10 X 10 X 10 X 10 X 10

Ex: 0.000045

Scientific Notation: 4.5 X 10-5

This is the same as saying 4.5 ÷ 10 ÷ 10 ÷ 10 ÷ 10 ÷ 10

Ex: 7.054 X 106

Ex: 4.7 X 10-7

Please complete 1-43 ODD on your own

The unit typically used in the sciences are those of the International System of Units.

Quantity SI base Unit Symbol

Length Meter m

Mass Kilogram kg

Temp Kelvin K

Time Second s

Amount of substance

Mole mol

1. How many years are in a CENTury?

2.How many CENTimeters are in a meter?• A centimeter is 1/100th of a meter

3.How many grams are in a KILOgram?

4.Take a look at the handout…

Making the connection…

We know that there are 100cm in 1 meter. But how do I determine how many centimeters are in an inch?

Accuracy: How does your value compare to a known (or accepted value)?

Precision: How does one of your values compare to all of them? If you take multiple measurements, are they all close in value?

Tips for the lab: It does not necessarily matter where you measure from exactly. Just be sure that the length you measure in inches is exactly that same length you measure in centimeters .

HW due Monday: pg 58-59 (#36 37, 38, 39, 44, 45, 46, 48, 49a, 52, 54, 55, 56, 67, 69, 70)

Tonight: Suggested Readings (3.1-3.3)

Tomorrow: Sig Figs (3.1)

Thursday: Dimensional Analysis (3.3)

Check out the Helpful websites – There is a good site describing physical and chemical properties and changes.