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Chemistry Terms
Term | Definition |
---|---|
accuracy | the closeness of a measured value to a standard or known value |
chemistry | the study of matter, its properties and the changes it undergoes |
control | a person, group, event, etc, that is used as a constant and unchanging standard of comparison in scientific experimentation |
conversion factor | ratio of the two parts of an equivalence statement that relate the two units |
density | the amount of matter present in a given volume of substance |
dependent variable | a variable that is being measured in an experiment |
error | used to assess accuracy with respect to how far a value if from what is expected |
experiment | a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact |
hypothesis | one or more assumptions put forth to explain observed phenomena |
independent variable | a variable that is manipulated in an experiment |
mass | the amount of matter an object contains |
matter | anything that has mass and occupies space |
observation | something that is witnessed and can be recorded |
percent error | used to assess accuracy as the relative difference, calculated as a percentage |
precision | the closeness of two or more measurements to each other |
qualitative measurements | collection of information that is not numerical |
quantitative measurements | measurement of data that can be put into numbers |
reliable knowledge | has a high probability of being true because it has been justified by a reliable method |
science | a system of knowledge and the methods used to find that knowledge |
scientific law | statement that summarizes generally observed behavior |
scientific method | a systematic method of collecting, analyzing, and communicating knowledge |
scientific notation | a power of ten with one digit to the left of the decimal point |
scientific theory | an interpretation; a possible explanation of why nature behaves in a particular way |
significant figures | the numbers recorded in a measurement (all the certain numbers plus the first uncertain number) |
units | part of a measurement that tells us what scale of standard is being used |
volume | the amount of space an object occupies |
megameters (Mm) | 10^6m 1 Mm = 1,000,000m |
Kilometer (km) | 10^3m 1 km = 1,000m |
Decimeter (dm) | 10^-1m 1 dm = 0.1m or 10 dm = 1m |
Centimeter (cm) | 10^-2m 1 cm = 0.01m or 100 cm = 1m |
Millimeter (mm) | 10^-3m 1 mm = 0.001 m or 1000mm = 1m |
Micrometer (um) | 10^-6m 1um = 0.000001m or 1,000,000um = 1m |
Nanometer (nm) | 10^-9m 1nm = 0.000000001m or 1,000,000,000nm = 1m |
100 cm | 1m |
1,000 mm | 1m |
10 mm | 1 cm |
1,000 m | 1 km |
1,000mg | 1 g |
1,000g | 1 kg |
1,000 mL | 1 L |
1cm^3 | 1mL |
1 mL | 1g |
sig figs nonzero (5783) | always significant |
423 find sig fig | three sig fig |
sig figs leading zeroes (.03) | never significant |
0.0025 find sig fig | two sig fig |
sig figs captive zeroes (3.05) | always significant |
20.06 - find sig figs | four sig fig |
sig figs trailing zeroes | only significant if the number is written with a decimal point |
200 - find sig fig | one sig fig |
2.00 - find sig fig | three sig fig |
exact numbers sig figs | not obtained by measuring; have an unlimited # of sig figs |