Physical Science chapters 1-4 vocabulary

a system of knowledge and the methods you use to find that know

the study of the composition, structure, properties, and reactions of matter

the study of matter and energy and the interactions between the two through forces and motion

the study of the origin, history, and structure of the Earth

the study of the universe beyond Earth, including the sun, moon, planets, and stars

life science

the use of knowledge to solve a practical problem

scientific method
an organized plan for gathering, organizing, and communicating information

information that you obtain through your senses

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

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

the straight-line distance between two points

the quantity of matter in an object or sample

the amount of space taken up by an object

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

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

the closeness of a measurement to he actual value of what is being measured

an instrument that measures temperature, or how hot an object is

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

a substance that cannot be broken down into simpler pieces

smallest particle of an element

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

the mixture that forms when a substance dissolves and forms a homogeneous mixture

a heterogeneous mixture that separates into layers over time

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

the tendency of a liquid to keep from flowing-its resistance to flowing

a material’s ability to allow heat to flow

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

a process that separates materials based not he size of their particles

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

a material’s ability to burn in the presence of oxygen

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

any solid that forms and separates from the liquid

the state of matter in which materials have a definite shape and a definite volume

the state of matter in which materials have a definite volume but not a definite volume but not a definite shape

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

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

when a substance absorbs energy from its surroundings

heat of fusion
the amount of energy needed to change a solid into a liquid

when a substance releases energy to its surroundings

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

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

the phase change in which a substance changes from a gas or vapor to a liquid

the phase change in which a substance changes from a solid to a gas or vapor without changing to a liquid first

when a gas or vapor changes directly into a solid without first changing into a liquid

a dense, positively charged mass located pin the center of the atom

a positively charged subatomic particle that is found in the nucleus of an atom

a negatively charged subatomic particle that is found in the space outside the nucleus

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

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

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