| A | B |
|---|
| system | a specific portion of matter in a given reion of space that has been selected for study during an experiment or observation |
| scientific method | a logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data |
| hyptothesis | testing statement or educated guess |
| model | an explanation of how phenomena occur and how data or events are related |
| theory | a broad generalization that explains a body of facts or phenomena |
| quantity | something that has magnitude, size, and amount |
| SI | International System of Units |
| weight | a measure of the gravitational pull on matter |
| derived units | combination of SI units |
| volume | the amount of space occupied by an object |
| density | the ratio of mass to volume, or mass divided by volume |
| conversion factor | ratio derived from the equality between two different units that can be used to convert from one unit to another |
| accuracy | refers to the closeness of measurements to the correct or accepted value of quantity measured |
| precision | refers to the closeness of a set of measurements of the same quantity made in the same way |
| percent error | calculated by subtracting the experimental value from the accepted value, dividing the difference by the accepted value, and then multiplying by 100. |
| significant figures | all the digits known with a certainty plus one final digit, which is somewhat uncertain or is estimated |
| directly proportional | dividing one quantity from the other gives a constant value |
| indirectly proportional | the product of two quantities of constant |
