Chapter 2: Analyzing Data Flashcards
Metric System
System used by common people in most countries
Systeme Internationale (SI)
Used by scientists
Temperature
Average kinetic energy
Density (D)
Mass (M)/Volume (V)
Kelvin (K)
Celsius (C) + 273
Extensive Properties
Change with size of sample
Ex: Volume, mass, weight, shape
Intensive Properties
Stays the same no matter the size; used to identify substances
Ex: Density, odor, taste, boiling point, melting point
Precision
Reproducibility
Accuracy
How close a value is to the true value
Significant Figures
Values that reflect the degree of precision of an instrument (how many decimal places may be reported)
Percent Error
Compares true values to observered values
% Error=(Observed-True)/True
How To Determine Number Of Significant Figures
- All nonzero digits are significant
- Zeroes between two significant figures are themselves significant
- Zeroes at the beginning of a number are never significant
- Zeroes at the end of a number are not significant unless a decimal point is written in the number
Addition And Subtraction With Significant Figures
Answers are rounded to the least significant decimal place
Multiplication And Division With Significant Figures
Answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation
Graphing Rules
- Data shields around points
- Independent variable on x axis
- Proportional scale
- Labeled axis
- Best fit trend line
- Title in “X vs. Y” format
- Units
Interpolation
Estimating values between plotted points (more reliable)
Extrapolation
Estimating values beyond plotted points (less reliable)
