Chapter 2: Atoms, Molecules, and Ions
Metals
- most elements - characteristic properties: efficient conduction of heat and electricity, malleability, and lustrous appearance - chemically metals tend to lose electrons to form positive ions - Cu = typical metal; widely used for electrical wires
Polyatomic/oxyanion ion suffixes
-ate: larger number of oxygen ions -ite: smaller number of oxygen ions
Dalton's Atomic Theory
1.) Each element is made up of tiny particles called atoms 2.) The atoms of a given element are identical 3.) chemical compounds form when different elements combine 4.) Reactions involve the reorganization of matter
Naming Type 1 Binary Compounds
1.) The cations is always named first and the anion second 2.) Monatomic (meaning one atom) cation takes a name of the element. (eg. Na+) 3.) A monatomic anion is named by taking the root of the element and -ide. Thus the Cl- ion is called chloride.
Naming Binary Covalent Compunds
1.) The first element in the formula is named first, using the full element name 2.) the second element is named as if it were an anion 3.) Prefixes are used to denote the numbers of atoms present. 4.) The prefix mono- is never used for naming the first element. For example, CO is called carbon monoxide, not mono carbon monoxide
C2H3O2
Acetate
Al3+
Aluminium
NH4+
Ammonium
Ba2+
Barium
Radioactivity
Becquerel found accidentally that a piece of mineral containing uranium could produce its impage on a photographic plate in the absence of light Emission of radium; Types of radio active emissions: - gamma (y) rayes: high energy light beta (B): high speed electrons apla particles: has 2+ charge
Be2+
Beryllium
Br-
Bromide
Ca2+
Calcium
CO3^2-
Carbonate
Cs+
Cesium
ClO3-
Chlorate
Cl-
Chloride
ClO2-
Chlorite
CrO4^2-
Chromate
Co2+
Cobalt (II) Cobaltous
Cu3+
Cobalt (III) cobaltic
Cr2O7^2-
Dichromate
H2PO4-
Dihydrogen phosphate
Nuclear Atom
Ernest Rutherford reasoned that if Thopmson's model were accurate, the massive L particle should crash through the foil like amo -many particles were deflected at large angles - an atom with a dense center of positive charge (the nucleus) w/ electrons moving around the nucleus at a distance
F-
Flouride
alkaline earth metals
Group 2A; beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and raduim (Ra) all form ions w/ a 2+ charge when they fact to nonmetals
Diatomic molecules
H2, Cl2, F2, I2, O2, N2, B2 Have no fear for ice cold beer
HPO4^2-
Hydrogen phosphate
HSO4-
Hydrogen sulfate
ClO- or OCl-
Hypochlorite
I-
Iodide
Fe2+
Iron (II) ferrous
Fe3+
Iron (III) Common Type II Cation Ferric
Electron
J.J Thompson studied electrical charges in partially evacuated tubes - Thompson found that when high voltage was applied to the tube, a "ray" he called a cathode ray b/c it emanated from the negative electrode Thompson postulated that the ray was a stream of negatively charged particles now called electrons charge-to-mass ratio
Pb2+
Lead II
Pb4
Lead IV
Li+
Lithuim
Mg2+
Magnesium
Hg2^2+
Mercury transition metal that only forms one type of cation therefore roman numeral is not used
Hg22+
Mercury (I)
Hg2+
Mercury II
NO2-
Nitrite
C2O4^2-
Oxalate
ClO4-
Perchlorate
MnO4
Permanganate
O2^2-
Peroxide
PO4^3-
Phosphate
K+
Potassium
Ag+
Silver
Na+
Sodium
NCS- or SCN-
Thiocyanate
S2O3^2-
Thiosulfate
Sn2+
Tin II tinous
Sn4+
Tin IV tinic
law of definite proportion
a given compound always contains exactly the same proportion of elements by mass (Proust)
polyatomic ions
also known as molecular ion, is a charged ion composed of two or more atoms covalentlyh bonded that can be considered as acting as a single unit
isotope
an atom w/ the same # of protons, but different #s of neutrons - because the chemistry of an atom is due to its electrons isotopes show almost identical chemical properties - in nature most elements contain mixtures of isotopes z= # of protons a= total # of protons and neutrons
monatomic Cations and Anions
an ion consisting on one atom Binary Type 1 atoms
nonmetals
appear in the upper right corner of the table, except hydrogen, a nonmetal that resides in the upper left corner - nonmetals often bond to each other by forming covalent bonds w/ non metals e.g. hydrogen chloride gas
Binary Covalent Compounds
are formed between two nonmetals. Although these compounds do not contain ions, they are named very similarly to binary ionic compounds
Avogadro's Hypothesis
at the same temperature and press equal volume of different gases contain the same number of particles
ionic bonding
b.c anions and cations have opposite charges they attract each other. - force of attraction between oppositely charged ions
Cd2+
cadmium
ionic solid
consisting of oppositely charged ions - ionic solids can consist of simple ions, as in sodium chloride or of polyatomic( many atom ions
Binary Ionic Compounds (Type 1)
contains a positive ion (cation) always written first in the formula and a negative ion (anion) - the metal present forms only a single type of cation
Cu2+
copper (II) cupric
CN-
cyanide
octa
eight
prefix penta
five
chemical bonds
forces that hold atoms together in compounds
Prefixes tetra
four
-ic
higher charge ends in -ic
H-
hydride
H+
hydrogen
HCO3-
hydrogen carbonate (bicarbonate is a widely used common name)
OH-
hydroxide
When more than 2 oxygen anions make up a series ______and_______are used as prefixes to name the members of the series with the fewest and most oxygen atoms.
hypo, hyper
structural formula
in which bonds are indicated by lines
ion:
is an atom or group of atoms that has a net positive or negative charge. Best known ionic compound = table salt
-ous
lower charge
Binary Ionic Compound (Type II)
many metals form more than one type of positive ions and thus form more than one type of ionic compound w/ a given ion eg. FeCl2 contains Fe2+ ions and the compound FeCl3 contains Fe3 ions--> charge on the metal ion must be specified with Roman numerals
law of conservation of mass
mass is neither created nor destroyed in a chemical reaction
alkali metals
members of Group 1A; Lithium (Li), Sodium (Na), potassium (K), rubidium (Rb), Cesuim (Cs), readily forms ions w/ a 1+ charge with nonmetals
halogens
members of Group 7A; fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At) - all form diatomic molecules - F, C, Br, and I all react with salts containing ions w/ a -1 charge (F-, Cl-, Br-, and I-)
Noble gases
membres of Group 8A- helium (He), neon (Ne), argon (Ar), Krypton (Kr), xenon (Xe), and radon (Rn) are known as noble gases - They all exist as a monatomic (single atom) gases have little chemical reactivity
anion
negative ion
nona
nine
N3-
nitride
O2-
oxide
P3-
phosphide
cation
positive ion
oxyanions
series of anions which contain an atom of a given element and different numbers of oxygen
prefix hepta
seven
covalent bonds
sharing electrons e.g H2, water (2O), oxygen (O2), ammonia (NH3), and methane (CH4)
space filling model
show the relative orientation in the molecule
prefix hexa
six
SO4^2-
sulfate
S2-
sulfide
SO3^2-
sulfite
chemical formula
symbols for the elements are used to indicate the toes of atoms present; subscripts are used to indicate relative numbers of atoms. Present and subscript are used to indicate relative numbers
