Chapter 1: Measuring Up

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Definitions

Matter = Anything that has mass and takes up space

Unit = Quantity that describes the measurement being made

Significant Figure = A digit in a measurement that contributes to the measurement's precision

Weight = Measure of how strongly gravity pulls on an object

Mass = Measure of how much matter exists in an object

Density = How tightly packed the matter in a substance is

Important Words

Matter

Precision

Unit

English Units

Metric Units

Unit Conversion

Factor-Label Method

Conversion Relationship

Base Unit

Meter

Centi

Milli

Kilo

Scientific Notation

Area

Derived Units

Volume

Graduated Cylinder

Meniscus

Experimental Error

Mass

Weight

Newton

Slug

Gram

Seconds

Density

Notes Chemistry is the study of matter and how it changes.

When using a ruler that is marked in 16ths of an inch report your answer in hundredths of an inch.

The unit of measurement is just as important as the number.

Precision of answer is determined by the instrument

Accuracy of answer is determined by correctness of measurement

When adding and subtracting measurements you must report your answer to the same precision as the least precise number in the problem.

When multiplying and dividing measurements you must report your answer to the same number of significant figures as the measurement which has the fewest significant figures.

There is always some error in the last significant figure in the measurement.

The curve of a liquid's surface is called the meniscus.

Rules for Significant Figures

All non-zero numbers are significant

A zero is significant if it is between 2 significant figures

A zero is also significant if at the end of the number and to the right of the decimal point.