Unit 1: Measurement & Lab Skills (Ch.1-3)

Precision

How exact your measurement is (number of decimal points), how repeatable.

Accuracy

Close to the true value.

Significant Figures

A system of rounding that communicates the precision of your measuring devices.

Keep it Real!

789 has three sig figs ~ all real numbers are significant.

Zero Sandwich

7008 has four sig figs ~ zeros in between real numbers are always significant.

Deciding Decimal

0.00009800 has four sig figs, the last two zeros are significant ~ for zeros to the right of the last real number, they are only significant if there is a decimal point in the number (anywhere in the number).

It's All about that Base!

2.00 x 10⁵ has three sig figs ~ all base numbers in scientific notation are always significant.

Hypothesis

An educated guess and testable statement.

Theory

Explains a natural phenomena (why), is widely accepted, and is based on observations of the natural world.

Law

Generalizes or describes an observation or pattern observed in the natural world.

Independent Variable

The ONE manipulated variable in a scientific experiment, is the "x" coordinate when graphing.

Dependent Variable

The outcome or result of your experiment that relies on your independent variable, is the "y" coordinate when graphing.

Controlled Variable(s)

Variable(s) kept the same so they are not tested during a scientific experiment and do not influence the dependent variable.

King Henry Died By drinking Chocolate Milk

A mnemonic device for the most common metric system prefixes... [kilo- hecto- Deka- (base unit) deci- centi- mili-].

Scientific Notation

A system of writing really, really large or small numbers in a shorter way.

Estimated Digit

In 7905.23, the three is the estimated digit. Measure your number to the last space on your measuring device, you will approximate the last digit in any measured value.

Leading Loser

0.00007 has 1 sig fig ~ zeros that lead a number, particularly a small number, NEVER are significant.