ch. 2 - measurements & calculations

Question 1

observation

Answer 1

using 5 senses to obtain info

Question 2

research

Answer 2

reliable sources to learn background info

Question 3

hypothesis

Answer 3

a testable statement that serves as a basis for predictions and further experimenting
(if… then… because); a proposal

Question 4

experiment

Answer 4

testing hypothesis in order to provide data that supports or refutes it

Question 5

qualitative data

Answer 5

descriptive (ex; texture, color)

Question 6

quantitative data

Answer 6

numbers (ex; graphs, counting, measuring)

Question 7

variables

Answer 7

experimental conditions that change or can be changed

Question 8

independent variable

Answer 8

is changed by experimenter, affects dependent dependent

Question 9

dependent variable

Answer 9

being tested and measured, affected by independent

Question 10

control

Answer 10

experimental conditions that stay constant/continuous; a comparison to another thing

Question 11

theory

Answer 11

BROAD GENERALIZATION used to explain observations; lots of evidence to support it but can change overtime

Question 12

model

Answer 12

PHYSICAL OBJECT that explains/illustrates complex concepts OR an explanation of how phenomena occur and how data/events are related

Question 13

weight vs mass

Answer 13

weight = measure of gravitational pull on matter
mass = measure of the quantity of matter; DOES NOT depend on gravity

Question 14

precision vs accuracy

Answer 14

precision = same results repeatedly
accuracy = matches up to actual data

Question 15

inversely vs directly proportionate

Answer 15

inversely = while one variable decreases, the other increases (product has a constant value)
directly = if one variable increases/decreases, the other does too (dividing one by the other gives a constant value)

Question 16

scientific notation (rules)

Answer 16

m(10^n) - m is greater than or equal to 1 but less than 10; n is a whole number
addition & subtraction = VALUES HAVE TO HAVE SAME EXPONENTS! – stay the same when # is added
multiplication = exponents are added
division = exponents are subtracted

Question 17

scientific method

Answer 17

a logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories supported by data

Question 18

what are SI measurements and what are the 7 base units?

Answer 18

a system that scientists worldwide agreed on
7 base units = meters (length), kilograms (mass), seconds (time), kelvin (temperature), mole (amount of substance), amperes (electric current), candela (luminous intensity)

Question 19

derived SI units

Answer 19

square meter (area), cubic meter (volume)

Question 20

density

Answer 20

ratio of mass to volume

Question 21

conversion factors

Answer 21

used to convert from one unit to another

quantity giver x conversion factor = quantity sought

Question 22

percentage error

Answer 22

experimental value minus accepted value divided by accepted value and multiplied by 100

Question 23

significant figures

Answer 23

consist of all the digits known with certainty plus one final digit, which is somewhat uncertain or estimated
addition/subtraction = answer has no more digits to the right of the decimal point than there are in # w/ smallest number of sigfigs to the right of decimal point
multiplication/division = answer has no more sigfigs than the # with the fewest sigfigs

Question 24

exact conversion factors

Answer 24

completely certain and don’t limit # of digits in calculation

Question 25

system

Answer 25

specific matter in a given region of space that has been selected for study during an experiment or observation.

Question 26

derived units

Answer 26

a combination of SI base units

Question 27

system

Answer 27

specific portion of matter in a given region of space that has been selected for study during an experiment or observation