Chapter 2 Flashcards
What are the SI Base Units?
- Length (l) *
- Mass (m)*
- Time (t)*
- Temperature (T)*
- Meter (m)
- Kilogram (kg)
- Second (s)
- Kelvin (K)
- Celsius (C)
- Amount of Substance (n)*
- Electric Current (I)*
- Luminous Intensity (I V (SUB)*
- Mole (mol)
- Ampere (A)
- Candela (cd)
There are how many base units are in SI?
7 base
What is a base unit?
Is a defined unit in a system of measurement that this based on an object
What is a derived unit?
A unit that is defined by a combination of base units.
What are two derived units?
Volume and density
What is Volume and what can it be calculated in?
The space occupied by an object.
- Solid object = cubic centimeter (cm^3)
- Liquids = milliliters (mL) or liters (L)
- 1 mL = 1 cm^3
What is the Density? The units for density?
- A ratio that compares the mass of an object to its volume
- The units for density: g/cm^3; g/mL
What is a conversion factor?
A ratio of equivalent values used to express the same quantity in different units.
What is a conversion factor is equal to?
1
A digit that must be _________ is called uncertain.
estimated
A ________ always has some degree of uncertainty.
measurement
What does accuracy refers to?
The agreement of a particular value with the true value/.
What does precision refer to?
The degree of agreement among several measurements made in the same manner.
Rules for Sig Figs
1). Non-Zero Rule: All digits 1-9 are significant
2). Straddle Rule: Zeros between two sig. figs. are significant
3). Decimal Rule: Zeros are the end of a decimal number AND anywhere to the right of a sig. fig, are significant
4). Coefficient in Scientific Notation: Any Zeros part of a number in scientific notation are significant
5). Not Significant: Any zeros at the beginning of a decimal number or used as a placeholder in a large number with no decimal point.
Rules for Significant Figures in Addition and Subtraction
Use the least number of places after the decimal between all the numbers you are adding or subtracting.
Rules for Significant Figures in Multiplication and Division
Use the least number of sig figs between the numbers you are measuring.
What is percent Error?
- Experimental values are measured during an experiment.
- Accuracy of experimental value can be compared quantitatively with accepted value by calculating the percent
Percent Error
Accept value = true value
Error (Experiment value - accepted value)
The lower the % error means lab technique is good
What are some observations?
- Making Measurements and collecting data
- Qualitative Vs. Quantitative
What is hypothesis?
- Testable Statement; statement to guide research
What is a prediction?
A guess of the outcome
Scientific Theory
Explains WHY natural phenomena occur
- Based on hypotheses
- Can be used to make predictions
- Can be revised
Scientific Law
Summarizes a set of observations about natural phenomena
- Based on hypotheses
- Can be used to make predictions
- Can be revised
Independent Variable
The one thing you change. Limit to only in an experiment
