chem112chapter1 Flashcards
matter
anything that has mass and takes up space
three states of matter
solid, liquid, gas
pure substance
matter that has distinct properties and a composition that does not vary from sample to sample.
elements
substances that cannot be decomposed into simpler substances; made of one kind of atom
compound
a substance which can be decomposed to simpler substances because it is made up of more than one element/atom
how many named elements
118
how many elements make up the earth’s crust
5
how many elements make up 90 percent of the human body by mass?
3
atom
building blocks of matter
the Law of Constant Composition
each compound have the same number of atoms of each element in every sample
mixtures
mixtures of different substances exhibit the properties that make them; each substance still has its chemical identity
heterogeneous
mixtures vary in composition throughout a sample
homogeneous
mixtures have the same composition throughout the solution
solution
a homogeneous mixture
energy
that capacity to do work or transfer heat
work
the energy transferred when a force exerted on an object causes a displacement of that object
heat
energy used to cause the temperature of an object to increase
force
any push or pull on an object
property
any characteristic that allows us to distinguish one type of matter from another
molecule
atoms joined together in specific shapes
physical properties
can be observed without changing the identity and composition of a substance
chemical properties
the way a substance may change, react, to form other substances
intensive properties
properties that do no depend on the amount of a sample being examined/used to identify substances
extensive properties
depend on the amount of a sample, such as mass and volume
physical changes
changes in matter that do not change the composition of a substance
Chemical changes
result in new substances
Converting between the three states of matter is a
physical change
in filtration
solid substances are separated from liquids and solutions.
in distillation
differences in the boiling points of substances to separate a homogeneous mixture into its component
in chromatography
substances are separated on the basis of differences in the ability of substances to adhere to the solid surface, in this case, dyes to paper
kinetic energy
it is the energy of motion; its magnitude depends on the object’s mass and its velocity
potential energy
of an object depends on its relative position compared to other objects
What does quantitative mean?
means a measurement has a numerical value
length
a measure of distance
mass
a measure of the amount of material in an object
volume
a derived unit from length (m × m × m = m3)
temperature
considered the “hotness and coldness” of an object that determines the direction of heat flow
density
has units that are derived from the units for mass and volume g/mL
exact numbers
are counted or given by definition
inexact (or measured) numbers
depend on how they were determined
precision
a measure of how closely individual measurements agree with one another
accuracy
a measure of how closely individual measurements agree with one another
