1.
activation energy: energy which two molecules must have to take part in a chemical reaction
2.
amphoteric: compound that can act as both a proton donor or proton acceptor
3.
anions: negatively charged ions
4.
atom: the smallest part of an element having the chemical properties of the element
5.
atomic number: usually located at the top portion of an element box on the periodic table
6.
atomic number: the positive charge on its atomic nuclei, or total number of protons in an atom
defines each element
7.
atomic structure and light-electron states: ground state
excited state
relaxation
electronic transitions
electromagnetic radiation
8.
atomic weight: usually located in the bottom of an element box of the periodic table
9.
atomic weight: the average mass of the atoms of various forms (isotopes) of an element, as they occur naturally
10.
balancing chemical equations: the relative number of moles of each product and reactant is indicated by placing a whole number coefficient before the formula of each substance in the chemical equation
the coefficient 1 is assumed when a numbered coefficient is absent
the equation, as written, is not balanced
we cannot alter any chemical substance in the process of balancing the equation
we can only introduce coefficients into the equation
we must never change subscripts
11.
basic symbols: plus sign (+) combines reactants or products
arrow (yield) shows direction of the reaction
single (---------->) reaction goes to completion generating products
double (======>) reversible reaction (equilibrium)
heat may be required to start a chemical reaction and may also be the product of a chemical reaction
the symbol used to represent heat is a small triangle
12.
boiling point: the temperature at which the pressure of the vapor escaping from the liquid equals the atmospheric pressure (760mm Hg or mercury)
13.
bronsted-lowery (proton acceptor): a compound that accepts a hydrogen ion is a base (anything that accepts a proton)
14.
bronsted-lowery (proton donor): a compound that donates a hydrogen ion, or proton, to another compound in a specific reaction is an acid
15.
catalysts: a substance that changes the rate of a reaction by lowering the activation energy without being permanently changed itself
16.
cations: positively charged ions
17.
charge: electricity due to the build-up of one of two kinds of electrical charges, either positive or negative
18.
chemical bonds: the electrical force of attraction between combining elements
19.
chemical equation: a qualitative and quantitative expression of the reacting substances and their products in a chemical reaction
20.
chemical formula: a combination of symbols of various elements that make up a compound
21.
chemical formulas: a chemical formula represents a molecule of a substance and is made up of the symbols of the elements of which it is composed
22.
chemical properties: a property that causes a substance to change into a new substance
23.
chemical reaction: a process in which one substance is changed into another
24.
chemical symbols: capitalized first letter of the english or latin name of the element or a single letter or a 2 letter representation for the element
25.
classical acid (arrhenius): a hydrogen containing substance that dissociates to produce hydrogen ions only in aqueous solution
26.
classical base: a chemical compound that yields a hydroxide ion in a water solution
27.
classifications of matter: pure substance
mixtures
28.
clinical importance of bases: digestion, absorption of food, nerve function, enzyme action and other biochemical reaction necessary for life
lime water (calcium hydroxide) is used to overcome excess acidity of the stomach
milk of magnesia (dilute solution of magnesium hydroxide) is used as an antacid, the suspension is used as a laxative
spirit of ammonia or smelling salts (ammonium hydroxide) heart and respiratory stimulant
29.
coefficients: used to indicate the number of molecules
30.
combination reactions: involve the direct union or combination of two substances producing one new substance
31.
combustion: (rapid oxidation) oxidation accompanied by noticeable light and heat
32.
complete chemical reaction: irreversible
33.
complex ions: ions composed of two or more covalently bonded atoms (radicals, polyatomic ions)
34.
compound: a substance that is characterized by constant composition and that can be chemically broken down into elements
35.
compounds containing two nonmetals: the chemical bond that exists between two nonmetal elements is predominantly covalent
the most electropositive element is named first
36.
concentration: rate or speed of a chemical reaction is proportional to the molecular concentration of each of the reacting substances
37.
concentration: the amount of a specified substance in a unit amount of another substance
38.
conclusions of Bohr: proposed a planetary model of the atom
39.
covalence: valence resulting from the sharing of electrons
40.
covalent bonds: involves a sharing of electrons resulting in the covalent bond
41.
decomposition reactions: reactions of a single substance being decomposed or broken down into two or more different substances
42.
density: the amount of mass per unit volume of a substance
it is the ratio of mass (M) to volume (V)
43.
dissociation of water (self-ionization of water): water has both acidic and basic properties, dissociation produces both the hydronium ion and hydroxide ion
44.
electrochemical reactions: deals with those chemical changes either produced by electric current or with the production of electric current
45.
electromagnetic radiation: energy released by atoms traveling as waves that can be broken into characteristic bands called wavelengths
46.
electronegativity: the relative tendency of an atom to gain an electron
47.
electronic transitions: the promotion and relaxation of electrons
48.
electrons: determine the chemical behavior of atoms
charge is negative one (-1)
mass is 1/1832 atomic mass unit (amu)
symbol is e or e-
electrical neutrality (protons equal to electrons)
electron configuration (arrangement of electrons)
49.
element: a substance that cannot be broken down into simpler substances by ordinary chemical means
50.
endothermic reactions: reactions that absorb energy
51.
energy: the ability to do work
mechanical, chemical, electrical, heat, nuclear, light
52.
energy levels: regions around a nucleus where electrons may be found
53.
equilibrium: when the rate of the forward reaction and the rate of the reverse reaction of a reversible reaction are equal, the reaction is said to have reached equilibrium
54.
equilibrium constant: ratio at equilibrium that is reached in a system when the conversion of reactants into products and the conversion of products back to reactants is the same
55.
example of chemical equation: sodium hydroxide reacts with hydrochloric acid to yield sodium chloride and water
NaOh + HCl ----------> NaCl + H2O
56.
excited state: when an electron absorbs energy, it travels from a lower energy level to a higher level
57.
exothermic reactions: reactions that liberate (release) energy
58.
five major factors that influence the rate of a reaction: 1 structure of the reacting species
2 concentration of the reactants
3 temperature of the reactants
4 physical state of the reactants
5 presence of a catalyst
59.
formula writing examples: aluminum fluoride-starting with the cation we can predict that aluminum has three valence electrons by looking it up on the chart of common elements
the anion fluorine is in group VII, it has 7 valence electrons, a -1 charge, it is necessary to multiply -1 x 3 to result in a zero charge
answer = AIF3
60.
gases: have neither a definite shape nor volume and are made of widely separated particles
properties are dependent on changes in temperature and pressure
designated by (g)
61.
general format of the periodic table: periods-7 horizontal rows
groups (families)-vertical columns
metals-substance whose atoms tend to lose electrons during chemical reactions. left side of the heavy staircase
nonmetals-found on the right-hand side of the heavy staircase
transition elements (heavy metals)-have incomplete inner shells
62.
ground state: the lowest possible energy condition of an electron
63.
heterogeneous: consist of more than one phase having visible differing parts
example: chocolate chip cookies, salt and pepper, and oil in water
64.
homogeneous: consists of only one phase
uniform mixture (the same throughout)
example: air, soft drink, ocean water
65.
hydronium ion: the product (H3O+)of a reaction between a hydrogen ion and a water molecule
66.
important groups of elements: alkali metals-group IA, do not occur as free elements
alkaline earth metals-group IIA, less reactive
transitional metals-group IB-VIIIB, conduct heat and electricity
halogens-group VIIA, extremely reactive
noble gases-inert gases-group VIIIA, completely unreactive
67.
incomplete chemical reaction: reversible
68.
ionic bonds: involves a transfer of one or more electrons from one atom to another, leading to the formation of an ionic bond
69.
ionic compound: contain two different elements (usually a metal and a nonmetal)
70.
ionic compounds: metals and nonmetals react to produce these compounds resulting from the transfer of one or more eleectrons
71.
ions: positively or negatively charged atoms or groups of atoms
72.
isotope notation: the representation of a specific isotope
the atomic number is listed below the symbol, the mass number above
73.
isotopes: atoms of the same element having different masses because they contain different numbers of neutrons
74.
kelvin: (K) measures extreme hot or cold
75.
kinetic energy (motion): energy a system possess by virtue of its motion
76.
law of conservation of mass: matter cannot be either gained or lost in a chemical reaction
the total mass of the products must equal the total mass of the reactants
77.
length: the distance between two points
expressed in meters (m)
78.
liquids: have no definite shape but have definite volume, which is independent of changes in temperature and pressure. designated by (l) or (aq)
79.
mass: the quantity of matter that an object contains
expressed in grams (g)
80.
mass number: the total number of protons and neutrons contained in the nucleus of an atom
81.
matter: that which has mass and occupies space
82.
melting point: the temperature at which a solid begins to change into a liquid
83.
mixtures: combination of two or more pure substances in which each substance retains its own identity
may be either homogeneous or heterogeneous
84.
modern theory: electrons do not move in simple orbits, like the planetary model suggested
85.
mole concept: a method that allows the relative number of reactant particles involved in a chemical reaction to be known
one mole of any substance will contain approximately 6.02x10 to the 23 power particles (avogadro's number)
86.
molecular collisions: are usually necessary for chemical reactions to occur
87.
molecule: a unit in which the atoms of two or more elements are held together by chemical bonds
88.
monoprotic acid: an acid that contains only one ionizable hydrogen ion or proton, per formula weight in solution
89.
neutralization: acid/base reaction
90.
nomenclature: the assignment of a correct and unambiguous name to each and every chemical compound
91.
nuclear structure of an atom (nucleus): protons-positive charge +1
neutrons-neutral charge
92.
octet rule: atoms try to attain the valence of their nearest noble gas neighbor
elements will gain, lose or share the minimum number of electrons necessary to have 8 electrons in their outermost shell
93.
orbital's: specific regions within energy levels where electrons are found
94.
outer structure of an atom: electrons
energy levels
orbitals
95.
oxidation: loss of electrons
addition of oxygen
removal of hydrogen
96.
oxidation-reduction: transfer of negative charge (one or more electrons) from one reactant to another
97.
oxidizing agents: a substance that gains electrons from another, causing the latter to be oxidized
98.
oxygen containing radicals (complex ions and polyatomic ions): oxygen containing ions with varying amounts of oxygen
less oxygen-"ite"
more oxygen-"ate"
99.
parentheses: used, along with the subscript, to indicate the number of complex ions present in a molecule
100.
pH: the molar concentration of hydrogen ions in a solution as expressed in the equation pH = -log[H+]
"p" is the negative power to which the number 10 must be raised and "H" is the molar concentration of hydrogen ions
101.
pH scale: has values that range from 0 (very acidic) to 14 (very basic)
a pH of 7, the middle of the scale, is neutral and neither acidic nor basic
normal blood pH is maintained from 7.35-7.45
102.
physical properties: properties such as color, height, or weight that do not involve a change in the chemical identity of the matter
103.
physical quantity: a property of matter to which we can assign both a numeric value and a unit of measurement
104.
physiological importance of acids: digestion
absorption of food
nerve function
enzyme action
other biochemical reactions necessary for life
105.
polar covalent bonds: when a covalent bond is formed between atoms of different electronegativities, the share pair of electrons stays closer to the more electronegative atom, and the resulting bond is polar
106.
polyprotic acid: acids that can donate more than one hydrogen ion or peoton, per formula weight in solution
107.
potential energy (chemical bonds): energy a system possesses by virtue of its position, condition, or composition
108.
products: written to the right of the reaction arrow
109.
products: substances resulting from a chemical reaction
110.
properties: characteristics of matter which are classified as chemical or physical
111.
properties of acids: taste-sour
litmus paper-turns blue litmus red
neutralization reaction (acid + base)
112.
properties of bases: taste-bitter or astringent taste
touch-slippery feeling (like soap)
litmus paper-turns red litmus blue
113.
pure substance: a substance that has only one component
114.
purpose of the periodic table: provides specific information about each element
organizes the elements according to physical and chemical properties
115.
reactants: substances resulting from a chemical reaction
116.
reactants: written to the left of the reaction arrow
117.
reducing agents: a substance that gives up electrons to some other substance, causing the latter to be reduced
118.
reduction: gain of electrons
removal of oxygen
addition of hydrogen
119.
relaxation: the release of energy by an atom resulting from electrons falling back into lower energy levels
120.
replacement reactions: single replacement-a reaction in which one atom or complex ions replaces another in a compound, producing a new compound
double replacement-a reaction in which two compounds react with each other and exchange atoms
121.
since water accepted the proton (H+ ion): it behaves as a base
122.
slow oxidation: oxidation not accompanied by noticeable light and heat
123.
solids: have a definite shape and a definite volume, which is independent of changes in temperature and pressure
124.
solubility: the amount of a substance that will dissolve in a specific volume of solvent at a given temperature
125.
specific gravity: the ratio of the density of that substance to the density of a substance used as a reference standard at the same temperature
126.
stable isotopes: atoms which do not breakdown spontaneously
127.
steps in formula writing (metal to non-metal): determine the proper symbol and valence of each element
place the positive element (cation) first and the negative last (anion)
balance the valences using subscripts by crossing over
128.
steps to a method for balancing chemical equations: step 1 count the number of atoms of each element on both the product and reactant side
step 2 determine which elements are not balanced
step 3 balance one element at ta time using coefficients
try to balance hydrogen last
step 4 check to be certain that the total mass of the products is equal to the total mass of the reactants
129.
stock system (official system): roman numerals placed in parentheses after the name of the metal are used to indicate its variable charge or oxidation state
130.
strong acids: ionize virtually 100% in water to yield hydronium ions (H30). strong acids are also strong electrolytes. hydrochloric (HCl) is a strong acid.
131.
strong bases: ionize virtually 100% in water to yield ions
a strong base will acquire a proton
132.
subscripts: a number placed below and to the right of the symbol
133.
symbols: a shorthand way to write the name of an element
134.
temperature: a physical property of a system related to thermodynamics
celsius (C) fahrenheit (F) Kelvin (K)
135.
types of chemical reactions: oxidation-reduction
electrochemical reactions
combination reactions
decomposition reactions
replacement reactions
neutralization
136.
unstable isotopes: radioactive isotopes, either natural or artificially created having an unstable nucleus that decays, emitting alpha, beta or gamma rays
137.
valence: the combining capacity of an element
138.
valence electrons: electrons in the outermost shell which are involved or have the potential to be involved in the bonding process
139.
volume: the size, measure, or amount of an object in three dimentions
expressed in liters (L)
140.
weak acids: do not ionize completely in water, yield much less than 100% hydronium ions. weak acids are also weak electrolytes. carbonic (H2CO3) is a weak acid
141.
weak bases: do not ionize completely in water
a base with a low tendency to gain a proton
