AP Chem Chapter 1 Flashcards
what is the scientific method
the process of studying natural phenomena, involving observations, forming laws and theories, and testing of theories during experimentation
what are the three main steps in the scientific method
- making observations
- formulating hypotheses
- performing experiments
what is a theory
a set of tested hypotheses that gives an overall explanation of some natural phenomenon
what is the difference between an observation and a theory
an observation is something that is witnessed and can be recorded. a theory is an interpretation, a possible explanation of why nature behaves a certain way
what is a natural law
a statement that expresses generally observed behavior
what is the difference between a theory and a law
a law summarizes what happens, a theory attempts to explain why it happens
what is the SI system
international system of units based on the metric system and units derived from the metric system
what is the difference between mass and weight
mass is a measure of the resistance of an object to a change in its state of motion
weight is a measure of the force that gravity exerts on an object
do all measurements have some degree of uncertainty
yes
true or false: we customarily report a measurement by recording to the first uncertain digit
true
what are sig figs
the certain digits and the first uncertain digit of a measurement
what is accuracy
the agreement of a particular value with the true value
what is precision
the degree of agreement among several measurements of the same quantity
what is a random error
a measurement has an equal probability of being high or low
what us a systemic error
occurs in the same direction each time; either always high or always low
under what circumstances is high precision among several measurements an indication of accuracy
if systemic errors are absent
do you round sequentially?
no. the number 6.8347 rounded to 3 sig figs is 6.83, not 6.84
do exact numbers ever limit sig figs
no
what is dimensional analysis
a method used to convert from one unit to another