Chapter 1: Keys to the Study of Chemistry Flashcards
(24 cards)
calibration
The process of correcting for systematic error of a measuring device by comparing it to a known standard.
Celsius scale
(formerly centigrade scale) A temperature scale in which the freezing and boiling points of water are defined as 0°C and 100°C, respectively.
chemical change
(also chemical reaction) A change in which one or more substances are converted into one or more substances with different composition and properties.
chemical property
A characteristic of a substance that appears as it interacts with, or transforms into, other substances.
combustion
The process of burning in air, often with release of heat and light.
composition
The types and amounts of simpler substances that make up a sample of matter.
density
D=M/v
dimensional analysis
(also factor-label method) A calculation method in which arithmetic steps are accompanied by canceling units that represent physical dimensions.
energy
The ability to do work, that is, to move matter. [See also kinetic energy (Ek) and potential energy (Ep).]
extensive property
A property, such as mass, that depends on the quantity of substance present.
heat (q)
(also thermal energy) The energy transferred between objects because of a difference in their temperatures only.
intensive property
A property, such as density, that does not depend on the quantity of substance present.
Kelvin scale
(also absolute scale) The preferred temperature scale in scientific work, which has absolute zero (0 K, or − 273.15°C) as the lowest temperature.
kelvin (K)
The SI base unit of temperature. The kelvin is the same size as the Celsius degree.
mass
The quantity of matter an object contains. Balances are designed to measure mass.
model
(also theory) A simplified conceptual picture based on experiment that explains how a natural phenomenon occurs.
natural law
(also law) A summary, often in mathematical form, of a universal observation.
random error
Error that occurs in all measurements (with its size depending on the measurer’s skill and the instrument’s precision) and results in values both higher and lower than the actual value.
SI unit
A unit composed of one or more of the base units of the Système International d’Unités, a revised form of the metric system.
systematic error
A type of error producing values that are all either higher or lower than the actual value, often caused by faulty equipment or a consistent flaw in technique.
temperature (T)
A measure of how hot or cold a substance is relative to another substance. A measure of the average kinetic energy of the particles in a sample.
uncertainty
A characteristic of every measurement that results from the inexactness of the measuring device and the need to estimate when taking a reading.
variable
A quantity that can have more than a single value. (See also controlled experiment.)
weight
The force that is exerted by a gravitational field on an object and is directly proportional to the object’s mass.
