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