Chemistry - Unit 1.B

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Science Outline - Unit 1 - B.0

Significant Figures

*Rules for Determining Sig Figs

All nonzero numbers are significant

Zeros may or may not be significant depending on their position in the number

Ex. 6.5 g --> 2 sig figs

132.34 --> 5 sig figs

18.00 --> 4 sig fgs

6.70 * 10^-3 --> 3 sig figs

*Rules for Rounding Significant Figures After Calculations

Addition and Subtraction: the answer should be rounded off so as to contain the same number of decimal places as the number with the least amount of decimal places

Example: 11.31 + 33.264 + 4.1 = 48.674 --> 48.7

2. Multiplication and Division: the answer should be rounded off to contain the same number of sig figs as found in the least accurate the value

Example: 5.282 * 3.42 = 18.06444 --> 18.1

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Measurement

*Rule for Measuring: ALWAYS include all certain digits (from tick marks) and one estimation (between tick marks or zero for on a tick)

Example: Blue Line = 13.31 cm

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Classification of Matter

*If the property can be determined without changing the identity of the substance --> Physical Property

Intensive: doesn't depend on the amount of substance

Density

Color

Texture

Hardness

Heat capacity

Malleability

Luster

Viscosity

Surface tension

Conductivity

Magnetism

Streak

Extensive: does depend on the amount of substance

Mass

Volume (3D)

Weight

Magnetic force