Warm-up1. Which number is the largest?

a. 1.13 x 109

b. 3.51 x 103

c. 5.88 x 105

d. 7.92 x 102

Which unit can be used to measure volume? a. mb. m2

c. m3

1. Which of the following units is the longest?a. meterb. centimeterc. kilometerd. millimeter

1-3 Scientific NotationPerform calculations involving scientific notation.

Determine significant figures.

Law vs. Theory

Law – a rule of nature

Answers the question “what?”

Examples: Law of Attraction and Repulsion, Law of Universal Gravitation

Theory – An explanation based on repeated experimentation and observation.

Answers the question “why”

Examples: Theory of Evolution, Atomic Theory

Law vs. Theory

Theories do not become laws!!! What doesn’t replace why!

A theory represents everything currently known about a topic.

Scientific NotationA number written as a product of two numbers: a coefficient and a power of 10 Designed for the expression of very big and very small numbers3.6 x 104

1 gram of hydrogen contains 301,000,000,000,000,000,000,000 molecules

3.01 x 1023 molecules

0.00081 = 8.1 x 10-4

Decimal moves 4 place to the right

34,000 = 3.4 x 104

Decimal move 4 places to the left

Significant FiguresA method of expressing error in measurement.

Measure a value and then estimate one degree below the limit of the reading .

5.35 cm

Significant FiguresAtlantic – Pacific Rule

Pacific – "P" is for decimal point is present Count significant digits starting with the first non-zero digit from the left. 0.004703 has 4 significant digits.18.00 also has 4 significant digits.

Atlantic – "A" is for decimal point is absent. Start counting significant digits with the first non-zero digit from the right.140,000 has 2 significant digits.20060 has 4 significant digits.

Examples50.3 3 SF

0.0008 1 SF

200200 4 SF

57.00 4 SF

490 2 SF

10000000 1 SF

1-3 SummaryWhat is scientific notation?Scientific notation is used to express very large or

very small numbers.

What are significant figures?Significant figures tell us how important the

numbers are.