1.3 Measurement

thermometer

"A thermometer is an instrument that measures temperature, or how hot and object is."

accuracy

"Accuracy is the closeness of a measurement to the actual value of what is being measured"

density

"Density is the ratio of an object's mass to it's volume. Density=Mass/Volume

volume

"For example, volume is amount of space taken ub by an object."

length

"In SI the base unit for length, or the straight-line distance between two points, is meters.

precision

"Precision is gauge of how exact a measurement is."

scientific notation

"Scientific notation is a way of expressing a value as a product of a number between 1 and 10 and a power of 10."

Why is scientific notation useful?

"Scientific notation makes very large or very small numbers easier to work with."

What units do scientist use for their measurements?

"Scientist use a set of measuring units called SI or the International System of Units."

significant figures

"Significant figures are all the digits that are known in a measurement, plus the last digit that is estimated."

mass

"The base unit for mass, or the quantity of matter in an object o sample, is kilogram (kg)."

How does the precision of measurements affect the precision of scientific calculations?

"The precision of a calculated answer is limited by the least precise measurement used in the calculation."

Temperature

Kelvin K

conversion factor

"A conversion factor is a ratio of equivalent measurements that is used to convert a quantity expressed in one unit to another unit."

Amount of substance

mole mol

Time

second s

Electric Current

ampere A

Luminous Intensity

candela cd