DE Chemistry – King William High School

 Cation – positive charge  lose an electron  Alkali metals (group 1) take a +1 charge  Alkaline earth metals (group 2) take a +2 charge  Group 13 takes a +3 charge

 Anion – negative charge  gains electrons  Halogens (group 17) take a -1 charge  Group 16 takes a -2 charge  Group 15 takes a -3 charge

 Sodium + fluorine  Magnesium + chlorine  Aluminum + oxygen

 Name the metal (if it is a transition metal put its charge in parentheses)  Name the nonmetal by using the “–ide” suffix  EX: K 2 S  EX: CuCl 3

 Nitrate (NO 3 - )  Nitrite (NO 2 - )  Sulfate (SO 4 -2 )  Sulfite (SO 3 -2 )  Carbonate (CO 3 -2 )  Bicarbonate (HCO 3 - )  Hydroxide (OH - )  Ammonium (NH 4 + )  Phosphate (PO 4 -3 )  Chlorate (ClO 3 - )  Cyanide (CN - )  Acetate (CH 3 COO - )  More listed on page 178 in table 6.7

 Beryllium + cyanide  Potassium + phosphate  Cobalt (II) + hydroxide

 Just name the polyatomic ion  EX: Al 2 (SO 4 ) 3  NH 4 Cl

 Covalent  they SHARE electrons  Lewis dot structures and the OCTET rule  EX: CH 4  O 2  N 2

 Must be in period 3 or greater  Usually for this class P, S and Cl  PCl 5  SF 6

 Use the prefixes…  Mono- (1), di- (2), tri- (3), tetra- (4), penta- (5), hexa- (6), hepta- (7), octa- (8), nona- (9) and deca- (10)  CO 2  Br 2 O

 Electronegativity – an atoms ability to attract the shared electrons in a bond  Closer you are to F!!!  EX: HCl  EX: water

 Polar covalent bonds do not share their electrons equally (HBr)  Nonpolar covalent bonds share their electrons equally (H 2 )  Page 189 – figure 6.7 shows actual electronegativity values

 BIG electronegativity difference in bond causing a “separation” of charge or dipole  EX: HF

 VSEPR theory – electrons and atoms are arranged as far apart from the central atom as possible  Linear – central atom has two other elements (EX: CO 2 ) – 180 degrees  Trigonal planar – central atom has three other elements (EX: CH 2 O) – 120 degrees  Bent – central atom with two elements and one lone pair (EX: SO 2 ) – 120 degrees

 Tetrahedral – central atom has four other elements (EX: CH 4 ) – 109 degrees  Trigonal pyramidal – central atom has three other atoms and one lone pair (EX: NH 3 ) – 109 degrees  Bent – central atom has two elements and two lone pairs (EX: water) – 109 degrees  Table 6.16 on page 194

 Symmetrical = nonpolar (EX: CH 4 )  Nonsymmetrical = polar (EX: water)

 Dipole-dipole (different elements bonded together)  Hydrogen bonds (hydrogen + SONF)  STRONGEST  Dispersion forces (between the same element)  WEAKEST