Qualitative vs. Quantitative Observations
1. Qualitative: Observations that describe the nature of something
example -- colour, shape, odour
2. Quantitative: Observations that involve measurements
example -- length, mass, density, volume
International System of Units (SI)
1. Length -- meter (m)
2. Mass -- kilogram (kg)
3. Time -- second (s)
4. Temperature -- Kelvin (K)
5. Amount of Substance -- mole (mol)
6. Electric Current -- ampere (A)
7. Light Intensity -- candela (cd)
Prefixes
1. mega- M 2. kilo- k 3. hecto- h 4. deca- da
5. deci- d 6. centi- c 7. milli- m 8. micro- µ
Use of SI System of Measurement
1. 75 cm (not 75cm) -- leave a space between the last digit and the unit.
2. 1.36 m (not 1.36 m.) -- don't put a period after the unit unless it is at the end of the sentence
3. 6 m (not 6 meters); six meters (not six m) -- use numbers and symbols together only!!
4. 0.25 cm (not 1/4 cm) -- use decimal fractions instead of fractions
5. 0.67 mm (not .67 mm) -- put a zero in front of a decimal if the number is less than 1
Accuracy, Precision, and Errors
1. Accuracy: how close is the measurement to its real value
2. Error: the difference between the observed value and the real value
2. Precision: how close are two observed measurements from each other that are made in the same way