structure of matter Flashcards
branch of science dealing with the chemistry of life forms
biochemistry
anything that has weight and takes up space
matter
chemical substance with only one type of atom
element
substance composed of two or more chemically bonded elements
compound
basic chemical substance needed in large quantity
bulk element
basic chemical substance needed in small quantity
trace element
basic chemical substance needed in very small quantity
ultratrace element
the smallest complete unit of the elements
atom
central core of an atom
nucleus
a small negatively charged particle that encircles the nucleus of an atom
electron
positively charged particle in an atomic nucleus
proton
electrically neutral subatomic particle
neutron
the number of protons in the atom of a particular element
atomic number
the number of protons plus the number of neutrons in each of an element’s atoms
atomic weight
an atom that have the same atomic number but different atomic weight
isotope
the state in which an isotope is unstable
radioactive
the energy or atomic fragments the unstable isotopes emit
atomic radiation
particle composed of two or more joined atoms
molecule
abbreviation for the number of atoms of each element in a compound
molecular formula
substance composed of two or more chemically bonded elements
compound
connection between atoms in a compound
bond
the path formed by an electron or several electrons encircling the nucleus of an atom at a particular energy level
electron shell
another name for electron shell because electrons have a level of energy characteristic of the particular shell they are in
energy shell
rule that says atoms react in a way that leaves the outermost shell completely filled with electrons to achieve a more stable structure
octet rule
to not be able to form chemical bonds because the outermost electron shell is filled; inactive
inert
an atom that becomes electrically charged from gaining or losing electrons
ion
a positively charged ion
cation
a negatively charged ion
anion
a bond where ions with opposite charges attract each other
ionic bond
bond produced when two atoms share electrons
covalent bond
representation of the way atoms bond to form a molecule, using symbols for each element and lines to indicate chemical bonds
structural formula
electrical charge not distributed symmetrically
polar
the attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule
hydrogen bond
the starting material that are changed by the chemical reaction
reactant
the atom, ions, or molecule formed at the reaction’s conclusion
product
process by which substances are united to form a new type of substance
synthesis
the breakdown of molecules into simpler compounds
decomposition
chemical reaction in which parts of two kinds of molecules trade positions
exchange reaction
chemical reaction in which the end products can change back into the reactants
reversible reaction
a molecule that influences the rates (not the direction) of chemical reactions but are not consumed in the process
catalyst
substance that dissolves in water and releases ions
electrolyte
substance that ionizes in water to release hydrogen ions
acid
substance that ionizes in water, releasing hydroxide ions (OH-) or other ions that combine with hydrogen ions
base
compound produced by a reaction between an acid and a base
salt
shorthand notation for the hydrogen ion concentration used to indicate the acidic or alkaline condition of a solution
pH scale
releasing equal numbers of acidic hydrogen ions and basic hydroxide ions
neutral
increase in the alkalinity of body fluids above pH 7.45
alkalosis
increase in acidity of body fluids below pH 7.35
acidosis
a chemical that resist pH change
buffer
