Chapter 1 Key Terms Flashcards
The process of studying natural phenomena, involving observations, forming laws and theories, and testing of theories by experimentation
Scientific method
Quantitative observation that always consists of 2 parts: a number and a unit
Measurement
Set of assumptions put forth to explain the observed behavior of matter
Model
One or more assumptions put forth to explain the observed behavior of nature
Hypothesis
Set of assumptions put forth to explain some aspect of the observed behavior of matter
Theory
A statement that expresses generally observed behavior
Natural law
Mass is neither created nor destroyed
Law of conservation of mass
International system of units based on the metric system & units derived from the metric system
SI system
The quantity of matter in an object
Mass
The force exerted on an object by gravity
Weight
The characteristic that any measurement involves estimates & cannot be exactly reproduced
Uncertainty
The certain digits and the first uncertain digit of a measurement
Significant figures
The agreement of a particular value with the true value
Accuracy
An error that has an equal probability of being high or low
Random error
The degree of agreement among several measurements of the same quantity; the reproducibility of a measurement
Precision
An error that always occurs in the same direction
Systematic error
Expresses a number as N • 10^M, a convenient method for representing a very large or very small number and for easily indicating the number of sig figs
Exponential notation
An equivalence statement between units used for converting from one unit to another
Unit factor method / dimensional analysis
A property of matter representing the mass per unit volume
Density
Anything occupying space & having mass; the material of the universe
Matter
Having visibly indistinguishable parts
Homogeneous mixture
The 3 different forms in which matter can exist; solid, liquid and gas
States (of matter)
Having visibly distinguishable parts
Heterogenous mixture
A homogeneous mixture
Solution
A change in the form of a substance, but not in its chemical composition; chemical bonds are not broken
Physical change
A substance with constant composition
Pure substance
A method for separating the components of a liquid mixture that depends on differences in the ease of vaporization of the components
Distillation
A method for separating the components of a mixture containing a solid and a liquid
Filtration
The general name for a series of methods for separating mixtures by employing a system with two phases (states) of matter: a mobile phase & a stationary phase
Chromatography
Use a strip of porous paper for the stationary phase, drop of mixture to be separated is placed on the paper, paper dipped into a liquid (mobile phase) that travels up the paper
Paper chromatography
A substance with constant composition that can be broken down into elements by chemical processes
Compound
The change of substances into other substances with different properties & different composition through a reorganization of the atoms; a chemical reaction
Chemical change
Substance that cannot be decomposed into simpler substances by chemical or physical means
Element
