Chemistry Chapter 2 Vocab

scientific method

a logical approach to solving problems by observing and collecting data

system

a specific portion of matter in a given region of space that has been selected for study

hypothesis

a testable statement

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, or amount

SI

a single measurement system called Le Systeme International d'Unites

weight

a measure of the gravitational pull on matter

derived units

combinations of SI base units

volume

amount of space occupied by an object

density

the ratio of mass to volume, or mass divided by volume

conversion factor

a ratio derived from the equality between two different units

dimensional analysis

a mathematical technique that allows you to use units to solve problems

accuracy

the closeness of measurements to the correct value of quantity measured

precision

the closeness of a set of measurements of the same quantity made in the same way

percentage error

calculated by subtracting the accepted value from the experimental value

significant figures

consists of all the digits known with certainty, plus one final digit, which is estimated

scientific notation

numbers written in the form M x 10^n, M is greater or equal to 1, but less than 10. N forms the number.

directly proportional

two quantities that can be divided by each other and give a constant value

inversely proportional

dividing the difference by the accepted value, and then multiplying by 100