unit 1 - essentials Flashcards
accuracy
how closely a measurement aligns with a correct value
atom
smallest particle of an element that can enter into a chemical combination
intensive property
property of a substance that is independent of the amount of the substance
extensive property
property of a substance that depends on the amount of the substance
compound
pure substnce that can be decomposed into two or more elements
homogenous mixture
(also, solution) combination of substances with a composition that is uniform throughout
heterogenous mixture
combination of substances with a composition that varies from point to point
physical change
change in the state or properties of matter that is not associated with any change in its chemical composition
chemical change
change producing a different kind of matter from the original kind of matter
chemistry
study of the composition, properties and interctions of matter
cubic centimeter
volume of a cube with a length of exactly 1cm
cubic meter
SI unit of volume
density
ratio of mass to volume for a substance or object
dimensional analysis
versatie mathematical approach that can be applied to computations ranging from simple unit conversions to more complex, multi-step calculations involving several different quantities
element
substance that is composed of a single type of atom; a substance that cannot be decomposed by a chemical change
exact number
number derived by counting or by definition
volume
amount of space occupied by an object
weight
force that gravity exerts on an object
Kelvin
SI unit of temperature; 273.15K = 0C
hypothesis
tentative explanation of observations that acts as a guide for gathering and checking information
kilogram
standard SI unit of mass; approx. 2.2 lbs
law
statement that summarizes a vast number of experimental observations and describes or predicts some aspect of the natural world
law of conservation of matter
when matter converts from one type to another or changes form, there is no detectable change in the total amount of matter present
liquid
state of matter that has a definite volume but indefinite shape
gas
state in which matter has neither definite volume nor shape
unit conversion factor
ratio of equivalent quantities expressed with different units; used to convert from one unit to a different unit
macroscopic domain
realm of everyday things that are large enough to sense directly by human sight and touch
mass
fundamental property indicating amount of matter
matter
anything that occupies space and has mass
meter
SI unit of length
microscopic domain
realm of things that are much too small to be sensed directly
milliliter
.001 liter; 1 cm^3
mixture
matter that can be separated into its components by physical means
molecule
bonded collection of two or more atoms of any element
physical property
characteristic of matter that is not associated with any change in its composition
plasma
gaseous state of matter containing a large number of electrically charged atoms and/or molecules
precision
how closely a measurement matches the same measurement when repeated
pure substance
homogenous substance with a constant composition
scientific method
path of discovery that leads from question and observation to law or hypothesis to theory, comined with experimental verification of the hypothesis and any necessary modification of the theory
SI units
standards fixed by international agreement in the International System of Units
significant figures
all of the measured digits in a determination, including the uncertain last digit
solid
state of matter that is rigid, has a definite shape and hs a fairly constant volume
symbolic domain
specialized language used to represent components of the macroscopic and microscopic domains, such as chemical symbols, chemical formulas, chemical equations, graphs, drawings and calculations
theory
well-substantiated, comprehensive, testable explanation of a particular aspect of nature
uncertainty
estimate of amount by which measurement differs from true value
unit
standard of comparison for measurements
ºC -> ºF
(ºC * 9/5) + 32 = ºF
element
substance that is composed of a single type of atom;
cannot be decomposed by a chemical change