| Terms |
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| Definitions |
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| Science |
use of knowledge in an organized and classified manner |
| Natural Science |
the study of the universe and its contents |
| Two categories of natural science |
physical and biological science |
| physical science |
the study of nonliving matter |
| biological science |
the study of living matter |
| Physics |
a branch of physical science that studies matter and enery and their interrelationships |
| Matter |
the substance that comprises all physical objects. It has shape and form and occupies space. Anything that has mass. |
| mass |
the quantity of matter contained in an object and is a principle characteristic of matter |
| weight |
the force that an object exerts under the influence of gravity |
| kilogram |
unit of mass |
| mixture of substances |
matter is most commonly found as this |
| substances |
a material that has a definite and constant composition |
| mixture |
two or more substances that have been combined |
| simple or complex |
substances may be one of what two things |
| simple substance |
is known as a element |
| complex substance |
is known as a compound |
| element |
a substance that cannot be broken down into any simpler substances by ordinary means |
| 92 |
# of naturally occurring elements |
| atom |
the smallest particle of an element that still possesses the chemical properties of that element |
| molecule |
when two or more atoms are chemically united and is the smallest particle of a compund that still possesses the characteristics of the compound |
| energy |
the ability to do work |
| Law of Conservation of Energy |
the sum total of all matter and energy in the universe is a constant: matter and energy cannot be created or destroyed but can be converted from one form to another |
| nucleus |
small dense center of the atom |
| nucleons |
protons and neutrons |
| protons and neutrons |
responsible for almost all the mass of an atom |
| electrons |
subatomic particle that cannot be divided into smaller parts |
| protons |
the key characteristic that distinguishes one element from another |
| atomic number |
the number of nuclear protons in an atom |
| Z number |
another name for the atomic number |
| atom becomes different element |
what happens when a atom loses or gains a proton |
| isotope |
if an atom loses or gains neutrons |
| ion |
if an atom loses or gains an electron |
| ionization |
the process of adding or removing an electron from an atom |
| electron binding energy |
that amount of energy needed to remove the electron from the atom |
| centrifiugal and attractive electrostatic force |
the stability of the electron orbit is contributed by these two opposing forces |
| electron volt (eV) |
the binding energy of an electron is measured in this unit |
| one |
shell number of K |
| two |
shell number of L |
| three |
shell number of M |
| four |
shell number of N |
| five |
shell number of O |
| six |
shell numper of P |
| seven |
shell Q |
| work |
the result of a force acting upon an object over a distance |
| mechanical energy |
the result of the action of machines or physical movement |
| potential and kinetic energy |
the two types of mechanical energy |
| potential energy |
the energy that an object has because of its position; stored by virtue of its position until it is converted to another form |
| kinetic energy |
the energy of motion |
| chemical energy |
form of energy released during a chemical reaction |
| thermal energy |
the result of motion of atoms and molecules |
| temperature |
a measure of thermal energy |
| electrical energy |
the result of movement of electrons |
| nuclear energy |
stored in the nucleus of each atom and holds the nuclear particles in a tight bond |
| electromagnetic energy |
a form of energy that is the result of electric and magnetic disturbances in space. travels through space as a combination of electric and magnetic fields and is produced by the acceleration of a charge |
| speed of light (c) |
the velocity of electromagnetic radiation in a vacuum |
| wave-particle duality of radiation |
EM radiation behaves as a particle or a wave depending on the circumstance |
| wavelength |
the distance between two successive crests or troughs |
| lambda |
character for wavelength |
| 0.1 - 0.5 angstroms |
the wavelength of diagnostic x-rays |
| amplitude |
the intensity of the wave defined by it maximal height |
| frequency |
the number of waves that passes a particular point in a given time frame, or the number of cycles per seconds |
| nu (v) |
the greek letter that represents frequency |
| inversely proportional |
the relationship between wavelength and frequency |
| waves |
electromagnetic energy travels through space in the form of this |
| particles |
when electromagnetic radiation interacts with matter in what form |
| photon or quantum |
small bundle of energy |
| directly proportional |
the relationship between the photon energy and frequency |
