Exam One Flashcards
(72 cards)
qualitative observation
information, in contrast, consists of nonnumerical observations, such as the color of a substance or its physical appearance
quantitative observation
information is numerical data, such as the mass of a substance
hypothesis
a tentative explanation or prediction in accord with current knowledge
theory
a well-tested unifying principle that explains a body of facts and the laws based on them
law
a concise verbal or mathematical statement of a behavior or a relation that seems always to be the same under the same conditions
describe the properties of matter in terms of kinetic molecular theory
according to this theory, all matter consists of extremely tiny particles (atoms, molecules, or ions) in constant motion
motioning and positioning of particles of any substance as a solid
particles are packed closely together, usually in a regular pattern
particles vibrate back and forth about their average positions but seldom do particles squeeze past their immediate neighbors to come into contact with a new set of particles
motioning and positioning of particles of any substance as a liquid
the particles are arranged randomly rather than in the regular patterns found in solids.
the particles are not confined to specific locations and can move past one another
motioning and positioning of particles of any substance as a gas
the particles are far apart
molecules move extremely rapidly and are not constrained by their neighbors. The molecules fly about, colliding with one another and with the container walls.
this random motion allows molecules to fill their container, so the volume of the sample is the volume of the container
relate changes of state to the transfer of heat (energy)
the higher the temperature, the faster the particles move
mixture
combinations of pure substances
pure substance
same composition throughout
homogeneous mixture
uniform mixtures
heterogeneous mixture
non-uniform mixtures
element
single type of atom
compound
two or more types of atoms
atoms
is the smallest particle of an element that retains the characteristic chemical properties of the element
molecules
particles consisting of more than one atom in which the atoms are held together by chemical bonds
ions
an atom or group of atoms that has lost or gained one or more electrons so that it is no longer electrically neutral
chemical properties
characteristics that determine how the composition of matter changes as a result of contact with other matter or the influence or energy
physical properties
a characteristic of matter that is not associated with a change in composition
example of chemical properties
flammability, toxicity, acidity
example of physical properties
density, color, hardness, melting/boiling points
intensive property
do not depend on the amount of substance
