Physical Science chapters 1-4 vocabulary

science
a system of knowledge and the methods you use to find that know
chemistry
the study of the composition, structure, properties, and reactions of matter
physics
the study of matter and energy and the interactions between the two through forces and motion
geology
the study of the origin, history, and structure of the Earth
astronomy
the study of the universe beyond Earth, including the sun, moon, planets, and stars
biology
life science
technology
the use of knowledge to solve a practical problem
scientific method
an organized plan for gathering, organizing, and communicating information
observation
information that you obtain through your senses
hypothesis
a proposed answer to a question
manipulated variable
the variable that causes a change in another
responding variable
the variable that changes in response tot he manipulated variable
controlled experiment
an experiment in which only one variable, the manipulated variable, is deliberately changed at a time
scientific theory
a well-tested explanation for a set of observations or experimental results
scientific law
a statement that summarizes a pattern found in nature
model
a representation of an object or event
scientific notation
a way of expressing a value as a product of a number between 1 and 10 and a power of 10
length
the straight-line distance between two points
mass
the quantity of matter in an object or sample
volume
the amount of space taken up by an object
density
the ratio of an object’s mass to its volume
conversion factor
a ratio of equivalent measurements that is used to convert a quantity expressed in one unit to another unit
precision
a gauge of how exact a measurement is
significant figures
all the digits that are known in a measurement, plus the last digit that is estimated
accuracy
the closeness of a measurement to he actual value of what is being measured
thermometer
an instrument that measures temperature, or how hot an object is
slope
the ratio of a vertical change to the corresponding horizontal change
direct proportion
a relationship in which the ratio of two variables is constant
inverse proportion
a relationship in which the product of two variables is a constant
pure substance
simply a substance
element
a substance that cannot be broken down into simpler pieces
atom
smallest particle of an element
compound
a substance that is made from two or more simpler substances and can be broken down into those simpler substances
heterogeneous mixture
the parts of the mixture are noticeably different from one another
homogeneous mixture
the substances are so evenly distributed that is difficult to distinguish one substance in the mixture from another
solution
the mixture that forms when a substance dissolves and forms a homogeneous mixture
suspension
a heterogeneous mixture that separates into layers over time
colloid
contains some particles that are intermediate in size between the small particles in a solution and larger particles in a suspension
physical property
any characteristic of a material that can be observed or measured without changing the composition of the substances in the material
viscosity
the tendency of a liquid to keep from flowing-its resistance to flowing
conductivity
a material’s ability to allow heat to flow
malleability
a material’s ability to be hammered without shattering
melting point
the temperature at which a substance changes from a solid to liquid
boiling point
the temperature at which a substance boils
filtration
a process that separates materials based not he size of their particles
distillation
a process that separates the substances in a solution based on their boiling points
physical change
when some of the properties of a material change, but the substances in the material remain the same
chemical property
any ability to produce a change in the composition of matter
flammability
a material’s ability to burn in the presence of oxygen
reactivity
the property that describes how readily a substance combines chemically with other substances
chemical change
when a substance reacts and forms one or more new substances
precipitate
any solid that forms and separates from the liquid
solid
the state of matter in which materials have a definite shape and a definite volume
liquid
the state of matter in which materials have a definite volume but not a definite volume but not a definite shape
gas
the state of matter in which a material has neither a definite shape nor a definite volume
kinetic energy
the energy an object has due to its motion
pressure
the result of a force distributed over an area
absolute zero
this temperature is equal of 0 K on the Kelvin temperature scale
Charles’s law
the law that states that the volume of a gas is directly proportional to its temperature in kelvins if the pressure and the number of particles of the gas are constant
Boyle’s law
the law that states that the volume of a gas is inversely proportional to its pressure if the temperature and the number of particles are constant
phase change
the reversible physical change that occurs when a substance changes from one state of matter to another
endothermic
when a substance absorbs energy from its surroundings
heat of fusion
the amount of energy needed to change a solid into a liquid
exothermic
when a substance releases energy to its surroundings
vaporization
when a substance changes form a liquid to a gas
heat of vaporization
the amount of energy need to change a liquid into a gas
evaporation
the process that changes a substance from a liquid to a gas at temperature below the substance’s boiling point
vapor pressure
the pressure caused by the collisions of this vapor and the walls of the container
condensation
the phase change in which a substance changes from a gas or vapor to a liquid
sublimation
the phase change in which a substance changes from a solid to a gas or vapor without changing to a liquid first
deposition
when a gas or vapor changes directly into a solid without first changing into a liquid
nucleus
a dense, positively charged mass located pin the center of the atom
proton
a positively charged subatomic particle that is found in the nucleus of an atom
electron
a negatively charged subatomic particle that is found in the space outside the nucleus
neutron
a neutral subatomic particle that is found in the nucleus of an atom
atomic number
an element equals the number of protons in an atom of that element
mass number
an atom is the sum of the protons and neutrons in the nucleus of that atom
isotopes
atoms of the same element that have different numbers of neutrons and different mass numbers
energy levels
the possible energies that electrons in an atom can have
electron cloud
a visual model of the most likely locations for electrons in an atom
orbital
a region of space around the nucleus where an electron is likely to be found
electron configuration
the arrangement of electrons in the orbital of an atom
ground state
when all the electrons in an atom have the lowest possible energies