Variable
The factor being tested in an e
Control
An experiment run without a va
order to show that any data fro
experimental setup was due on
variable that was being tested
Hypothesis
Proposed solution to a scientif
Law
Summarizing statement observ
experimental facts that has be
many times and is generally ac
true
Conclusion
A solution to a scientific proble
Theory
A logical, time-tested explanat
events that occur in the natura
Mass
The amount of matter in an ob
Weight
Measure of the force of attract
between objects due to gravity
Density
Mass per unit volume
Temperature
Measure of the motion of mole
Matter
Anything that has mass and vo
Gravity
Force of attraction that depend
mass of two objects and the di
between them; responsible for
accelerating an object toward t
Volume
Amount of space an object tak
Inertia
Tendency of objects to remain
or to stay at rest unless acted
outside force
Chemical change
Process by which a substance
a new and different substance
Physical change
Process by which a substance
phase
Plasma
Phase in which matter is extre
in energy and cannot be conta
ordinary matter; very rare on E
in stars
Condensation
Change of a gas to a liquid
Evaporation
Vaporization that takes place a
surface of a liquid
Vaporization
Change of a liquid to a gas
Sublimation
Change from the solid phase d
the gas phase
Amorphous
Solids that lose their shapes u
certain conditions
Crystal
Solid in which the particles are
in a regular repeating pattern
Element
Simplest type of pure substanc
Compound
Substance made up of molecu
contain more than one kind of
or more elements chemically c
Mixture
Matter that consists of two or m
substance mixed; but not chem
combined
Heterogeneous
Substance that does not appea
same throughout
Homogeneous
Substance that appears to be
throughout
Soluble
Can be dissolved in another m
such as water
Insoluble
Cannot be dissolved in anothe
Colloid
Homogeneous mixture in whic
particles are mixed together bu
dissolved
Solvent
Substance that does the disso
solution
Solution
Homogeneous mixture of a few
substances in a single physica
Solute
Substance that is dissolved in
Alloy
A solution of two metals or a m
nonmetal that has the propertie
metal
Atom
The smallest part of an elemen
all the properties of an elemen
Molecule
Combination of atoms formed
covalent bond
Nucleus
The center of an atom
Proton
A positively charged particle in
nucleus of an atom
Neutron
A neutral particle in the nucleu
atom
Electron
A negatively charged particle f
area outside the nucleus of an
Isotopes
Atom that has the same numb
protons (atomic number) as an
but a different number of neutr
Energy
The ability to do work
Atomic Number
Number of protons in the nucle
atom
Atomic Mass
Weighted average of the mass
of an element's naturally occur
isotopes
Ductile
Able to be drawn into a thin wi
Malleable
Able to be hammered out into
Valence
Electron in the outermost ener
an atom
Alkali Metals
Member of element Family 1 th
valence electron
Inert
Member of Family 18 of the pe
table; elements have atoms wi
valence electrons and unreact
Ion
An atom that has become char
the loss or gain of electrons
Metalloid
Element that has properties of
metals and nonmetals
Covalent bond
Bone that involves the sharing
electrons
Ionic bonds
Bond that involves the transfer
electrons
Electron affinity
Tendency of an atom to attract
Diatomic
Element whose atoms can form
bonds with another atom of the
element
Polyatomic ion
Group of covalently bonded at
acts like a single atom when co
with other atoms
Reactant
Substance that enters into a ch
reaction
Product
Substance produced by a chem
reaction
Synthesis
Chemical reaction in which two
simple substances combine to
new, more complex substance
Single Replacement
Chemical reaction in which an
uncombined element replaces
that is part of a compound
Double Replacement
Chemical reaction in which diff
atoms in tow different compou
each other
Endothermic
Chemical reaction in which ene
absorbed
Exothermic
Chemical reaction in which ene
released
Activation energy
Energy required for a chemica
occur
Acid
Compound with a pH above 7
our, turns blue litmus paper red
hydrogen ions
Base
Compound with a pH above 7
bitter, is slippery to the touch, t
litmus paper blue
pH
Measure of the Hydronium ion
concentration, scale 1-14
Hydronium ions
A positively charged hydrogen
Hydroxide
A negatively charged oxygen a
hydrogen molecule
Radioactivity
Release of energy and matter
form changes in the nucleus o
Fusion
Joining of two atomic nuclei of
mass to form a single nucleus
mass
Half-life
Amount of time it takes for half
atoms in a given sample of an
decay
Decay
Sequence of steps by which a
nucleus decays into a nonradio
nucleus
Velocity
Description of speed in a given
Speed
Rate at which an object moves
time
Acceleration
Rate of change in velocity
Deceleration
The decrease in the velocity o
Momentum
Mass of an object time its velo
Force
Push or pull that gives energy
object, sometimes causing a c
the motion of the object
Pressure
Force that particles if a fluid ex
certain area due to weight and
Buoyancy
Upward force in a fluid that exi
because the pressure of a fluid
with depth
Work
Force acting over a distance to
object
Power
Rate at which work is done or
used
Resistance force
Opposition to the flow of electr
Mechanical advantage
Number of times a machine m
effort force
Efficiency
Comparison of work input to w
Fulcrum
Fixed pivot point of a lever
Simple machine
An instrument that makes work
Compound machine
One or more simple machines
together
Energy
Ability to do work
Mechanical energy
Energy associated with motion
Nuclear energy
Energy released when a nucle
combines
Chemical energy
Energy that bonds atoms or io
Heat energy
Energy involved in the internal
particles of matter
Electromagnetic energy
Energy associated with moving
Potential energy
Energy of shape or position, st
energy
Kinetic energy
Energy of motion
Gravitational potential energy
Potential energy that is depend
height above the Earth’s surfa
Heat
Form of energy caused by the
motion of molecules of matter
Kelvin
Metric temperature scale which
represents absolute zero . Wa
at 273 K and boils at 373 K.
Convection
Heat transfer in liquids and ga
means of rising and falling.
Conduction
Heat transfer through direct co
Radiation
Heat transfer through space
Specific Heat
Ability of a substance to absor
energy
Thermal expansion
Expansion of a substance due
Insulation
Prevention of heat loss by redu
transfer of heat by conduction
convection
Absolute zero
Temperature at which all mole
motion ceases; lowest possible
temperature
Calorimeter
Instrument used to measure th
given off in chemical reactions