IPC Chapter 4-5

alchemists

scientists who were interested in turning low-value material such as lead into high value substances like gold

triads

a model of periodicity developed by Johann Dobreiner that is based on groups of three elements with similar properties

periodicity

the idea that the properties of elements repeat in regular repeating patterns in relation to some basic characteristics such as atomic mass or atomic number

law of octaves

the principle published by chemist John Newlands that stated that the properties of the forty-nine then known elements repeated every eighth element as in a musical octave

periodic law 

the law that states that the properties of elements vary in their tomic numbers in a regular, repeated pattern 

periodic table of the elements

a tale of chemical elements arranged to display their periodic properties in relation to their atomic numbers

family/group

a column of elements in a periodic tale having similar valence electron arrangement, resulting in similar chemical properties

valence electrons

any electron in the outermost energy level of a neutral atom. Unpaired valence electrons are usually involved in chemical bonding

period

a row in the periodic table of the elements, also called a series

metal 

an element that is typically dense, solid, ductile, malleable, highy conductive, and chemically reactive, especially in the presence of non metals

metalloids

an element with characteristics between those of a metal and a nonmetal, located between metals and nonmetals on the periodic table

nonmetals

an element that typically has four or more valence elecrons and that does not exhibit the general properties of metals; located on the right side of the periodic table

alkali metals

an element in group 1 of the periodic table, having one valence electron that it can easily lose to form a 1+ cation, making it extremely reactive, the most reactive of all metals

alkali earth metals

an element in group 2 of the periodic table, having 2 valence electrons that it tends to loose easily to become a 2+ cation, making it very reactive

transition metal 

any elements in groups 3-12 of the periodic table, typically having one or two valence electrons, which it easily loses, resulting in cations with charges of 1+ or 2+ 

inner transition metals

an element from either of two rows, usually placed below the periodic table; a member of either the lanthanides or the actinides. Typically have two valence electrons

lanthanides

silvery white metals that form oxides when exposed to air- “rare earth metals” , abundantly distributed throughout the earth but not in places where it can be mined. Used in optical devices, petroleum refining, and alloys

actinides

radioactive, unstable, decay into other elements, synthetic/man-made metals used to power devices such as cardiac pacemakers)

mixed group

any of groups 13-16 in the periodic table; so named because they contain metals, nonmetal, and metalloids. These groups are often named for the first element in their family

halogen

an element in group 17 of the periodic table having seven valence electrons. It easily gains an electron, forming a 1- anion, which causes it to be highly reactive

noble gases

an element in group 18 of the periodic table having 8 valence electrons that fill the outermost energy level (helium is an exception with only 2). with a full energy level, it is inert/nonreactive

electron dot notation

consists of the element’s chemical symbol surrounded by the atom’s valence electrons. The chemical symbol represents the nucleus and all of the non-valence electrons

atomic radius

distance from the center of an atom’s nucleus to the electrons in the outermost energy level

electronegativity 

the measure of an element’s ability to attract and hold electrons when bonded to other atoms 

chemical bond

an electrostatic attraction that forms between atoms when they share or transfer electrons

octet rule

the principle that states that atoms generally are most stable when they have 5 electrons in their valence energy level

covalent bond

a chemical bond formed as a result of two atoms sharing valence electrons

ionic bond

a chemical bond formed as a result of two atoms sharing valence electrons

formula unit 

the smallest whole number ratio of ions within an ionic compound 

metallic bond

the attraction between metal atoms and their collectively shared valence electrons

diatomic molecule

a molecule made of two atoms

Lewis structure

a system for modeling the covalent bonds between atoms in a molecule and any unbonded electrons in the molecule

chemical formula

a shorthand way of identifying a chemical compound consisting of element symbols and superscripts that represent the # of atoms of each element

binary compound 

a compound made from only two elements 

polyatomic ion

a group of covalently bonded atoms that together have gained or lost an electrons and act as a single ionized particle

oxidation states

positive or negative number showing the electric charge of an element when it forms a compound

Robert Boyle

began transition from alchemy to chemistry; solidified that matter was made of indivisible particles theory, in 1661, published Skeptical Chemyst- “experimentation to to be that basis of science”

Antione Lavoisier

in 1779, while researching combustion reactions, he demonstrated that combustion required oxygen . Made on of the first lists of the then-known elements, thirty-three exactly