Unit 1: Into and Atomic Theory Flashcards
Scientific Method
Ask a question, do background research, construct a hypothesis, experiment, analyze data, make a conclusion
Qualitative Data
Involves observations, words and descriptions of observations
Quantitative Data
Involves measurements, number
SI units (length)
meter (m), tool to measure is ruler/meter stick
SI units (mass)
kilograms (kg), tool to measure balance
SI units (time)
seconds (s), tool to measure is clock/stopwatch
Metric Prefixes (H)
hecto, 10^2 base
Metric Prefixes (K)
kilo, 10^3 base
SI units (temperature)
kelvin (k), tool to measure is thermometer
SI units (amount of substance)
mole (mol), no tool of measure
derived unit
combination of basic SI units (density, volume)
Metric Prefixes (D)
deka, 10^1 base
Metric Prefixes (base)
meter, liter, gram, second
Metric Prefixes (d)
deci, 10^-1 base
Metric Prefixes (c)
centi, 10^-2 base
Metric Prefixes (m)
milli, 10^-3 base
Metric Prefixes (u)
micro, 10^-6 base
Metric Prefixes (n)
nano, 10^-9 base
Metric Prefixes (p)
pico, 10^-12 base
Metric System
1 cm^3 = 1 mL
Dimensional analysis
A method of problem-solving that focusis on the units used to describe matter (Metric Prefixes)
Significant Figures
Non-zero digits are always significant, any zero between sig figs are significant, any zero in front of non-zero digits aren’t significant, a final zero or trailing zeros in the decimal portion only are signifcant
Precision
How close a series of measurements are to each other (consistent/reproducible)
Significant Figures (add/subtract)
fewest amount of decimal places
Accuracy
How close a measurement is to the accepted value
Significant Figures (multiply/divide)
use the fewest number of sig figs
Percent Error
Percent Error = ( |experimental value - actual value| / actual value )*100
Systematic Errors
Affects all measurements taken (ex. forgetting to calibrate a balance/scale)
Personal Errors
Never say “human error” (ex. not using proper or precise experiment; timing an experiment inconsistently)
Random Errors
Fluctuations in experimental/measurements (ex. not in stable conditions; physical/environmental errors)
What is the acceptable margin of error in science?
+/- 10%
Most common type of graph in chemistry?
Line graph