Upload
jonesflyrod
View
469
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Citation preview
The attraction between atoms in a molecule or crystalline structure
When elements react atoms must collide
Bond that results when metal atoms release their valence electrons to a pool of electrons shared by all the metal atoms
Holds metals together Results in high conductivity,
malleability, and ductility
Composed of positively and negatively charged atoms Metals on left form compounds with
nonmetals on right Form ionic bonds- a chemical bond
between two ions with opposite charges
EXAMPLE: NaCl
Crystallinesolids
High melting and boiling points Shatter May be water soluble
Electrically neutral because same number of protons and electrons
Gaining or losing 1 or more electrons, atom can be converted into charged particle called ion.
Ion- an atom or group of atoms that has a positive or negative charge
Cations- positive ion, fewer electrons than protons, lose electronsPositive charge on a cation= number of electrons
lostEx. Neutral Mg atom loses 2 electrons Mg2+ ion
Anions- negative ion, more electrons than protons, gain electronsnegative charge on nonmetal anion equals the
number of electrons gainedEx. S gains 2 electrons, sulfide ion S2-
Charge on atom Group 1,2,3 A form charges equal to the
group number (+1, +2, +3) Nonmetals 5, 6, 7 A have negative
charge usually equal to 8 – A group # (-3, -2, -1)
More than one stable ion Examples:
Fe2+ and Fe3+
Cu+ and Cu2+
Many transition metals form 2+ ions.
Octet rule: atoms become stable by having 8 electrons in their outer energy level except some of the smallest atoms which have only 2
Noble gases lack reactivity (stable)(8 electron) Elements stable by achieving configuration of
valence electron of 1 of noble gases. (Share or transfer electrons)
Main group metals react so have an electron configuration like the noble gas before them
Main group nonmetals react so they have an electron configuration like that of the noble gas after them
Dots around atomic symbol represent the number of valence electrons
Write electron dot for Radon (Rn), Lead (Pb), and Xenon (Xe)
Group 1A 2A 3A 4A 5A 6A 7A 8A
# Valence electrons
# e- gained/ lost *
Charge on stable ion
*How many electrons must be gained or lost to satisfy octet rule?
MUST BE ELECTRICALLY NEUTRAL (0) Have the lowest possible number of each
type of atom (Formula unit) Subscripts indicate number of ions Cations always written first and charges are
not included!!
Cation first, anion second Cation of Main Group elements
Simply use the name of element it is formed fromEx: Na+, sodium ionCation of Transition Metals- Use name of the element it is formed from AND
charge designated by a Roman Numeral in ( )- Ex: Fe 3+, Fe (III) ion
AnionReplace ending of name with _____________Examples:
fluoride, chloride, bromide oxide, sulfide, selenide, nitride, phosphide, arsenide
Name the following ionic compounds:MgCl2 FeF3
LiBr ZnO
Al2O3 Na2S
Table 3-8, p.96
Several atoms bound together that collectively have a charge:
3-
Example: phosphate ion
Name the following ions:
NO3-
CN-
OH-
Write the formulas of the following ions: Phosphate ion
Ammonium ion
Permanganate ion
Parentheses may be needed for polyatomic ions
EXAMPLE:aluminum hydroxide ____________________ammonium phosphate___________________sodium sulfate_________________________
p.95a
Magnesium phosphate
1. List Cation first, anion second Ex. NaCl NOT ClNa
2. Don’t write charges of ions Ex. KF NOT K+F-
3. Use parentheses around a polyatomic ion formula if it has a subscript
Ex. Al2(SO4)3 NOT AL2SO4 3
Name the following compounds:
CuO
NaNO3
NH4Cl
Write formulas for the following compounds:
Barium Hydroxide
Copper (II) carbonate
Magnesium bicarbonate