MATERIAL SCIENCE CH 3 PRE QUIZ VOCAB

anion

ion with extra electron and negative charge 

covalent bonding

stable electron configurations are assumed by the sharing of electrons between adjacent atoms 

electron shell

the region around an atom’s nucleus where electrons are likely to be found. they determine the atom’s chemical behavior

ground state

when all the electrons occupy the lowest possible energies in accord with the foregoing restrictions

ion

an atom that has gained or lost one or more electrons, thereby gaining an electrical charge

metallic bond

the final primary bonding type is found in metals and their alloys. approximates the bonding scheme, they are more or less free to drift throughout the entire metal

nucleus

positively charged of an atom, consisting of protons and neutrons

planetary model

refers to the Bohr model of the atom. Describes electrons as orbiting the nucleus in circular orbits, or shells, similar to how planets orbit the sun

photon

represents a quantum of electromagnetic radiation, playing a crucial role in various chemical processes 

quantum mechanics 

set of principles and laws that govern systems of atomic and subatomic
(protons, neutrons, and electrons) entities 

shells

specified a principal quantum number, n, which may take on integral values beginning with unity (n=1,2,3,4,5,..,)

valence shell

outermost electron shells of an atom, containing the valence electrons that are crucial in determining the atom’s chemical behavior 

atom

smallest complete unit of an element (proton, neutron, electron)

electron

negatively charged particle that orbits the nucleus of an atom

element

consists of atoms with the same number of protons in their nuclei

groups

periodic table sorted into columns (left to right)

ion core

possess a net positive charge equal in magnitude to the total valence

metal

high electrical and thermal conductivity, malleability, ductility, and high reflectivity of light

neutron

neutral subatomic particle found in the nucleus of an atom, with a mass similar to that of a proton and no electric charge. determines the isotope of that element 

periodic table 

all the elements have been classified according to electron configuration

primary bonds 

3 different types are found in solids–ionic, covalent, and metallic. For each type, the bonding involves the valence electrons. The bond depends on the electron structures of the atoms 

sea of electrons

belonging to the metal as a whole

subshells

divisions of electron shells that contain orbitals where electrons reside (s,p,d,f)

van der waals bonds

aka secondary or physical  bonds; much weaker than primary bonds. Are significant between gasses. Made up of inert elements or between covalently-bonded molecules

cation 

ion that has given up an electron and has a positive charge 

electron cloud

describes the area surrounding an atomic nucleus where electrons are most likely to be located

excited state

condition of an atom or molecule in which its energy is higher than the ground state 

hydrogen bond

a special type of secondary bonding, is found to exist between some molecules that have hydrogen as one of the constituents

ionic bond

always found in compounds that are composed of both metallic and nonmetallic elements, elements that are situated at the horizontal extremities of the periodic table

molecule

two or more atoms that have bonded together

pauli exclusion principle

each electron state can hold no more than 2 electrons, which must have opposite spins 

periods

increasing atomics number, in 7 horizontal rows. Arrayed in a given column or group have similar valence electron structures, as well as chemical and physical properties

proton

positively charged subatomic particle found in the nucleus of every atom, playing a crucial role in defining the atomic number and properties of elements 

secondary bonding 

much weaker than primary bonds. Exists between virtually all atoms or molecules, but its presence may be obscured if any of the 3 primary bonding types are present

valence electrons

those that occupy the outermost shell. Extremely important, they participate in the bonding between atoms to form atomic and molecular aggregates

wave mechanical model 

the electron is considered to exhibit both wave-like and particle-like characteristics. With this model, the electron is no longer treated as a particle moving in a discrete orbital; rather, a position is considered to be the probability of an electron’s being at various locations around the nucleus