Measurements Flashcards
International System of Units
a revised version of the metric system that was adopted by international agreement in 1960
Derived units
a combination of different base units (a number of units in the SI system are derived)
Absolute zero
the zero points on the kelvin temp. scale (-273.15 c)
Metric units of length
meter, kilometer, nanometer, centimeter
Units of volume
cubic meter, liter, millimeter, cubic centimeter, microliter
Units of Mass
kilogram, gram, milligram, microgram
Units of temperature
celsius and kelvin
Units of the amount of a substance
mole, atomic mass of an element or molar mass of a compound
accuracy
a measure of how close a measurement comes to the actual value of whatever is being measured
precision
a measure of how close a series of measurements are to one another
how do you evaluate the accuracy of a measurement?
the measured value must be compared to the correct value
how do you evaluate the precision of a measurement?
compare the values of two or more repeated measurements
density
the amount of mass per unit volume (m/v). it can help to identify a substance and is affected by temperature
what are the units of density
kg/m^3, g/cm3, g/mL which are derived.
