Chapter 7

Representative elements of the same groups usually have
the same ionic charges.

Group 1: H+, Li+, Na+

Group 2: Be2+, Mg2+, Ca2+

Group 15: N3-, P3-, As3-

Group 16: O2-, S2-, Se2-

Group 17: F-, Cl-, Br-

Transition elements can usually have more than one
charge. Example Fe2+ and Fe3+

Most transition metals can have a few
different charges.
Example:
Fe2+, Fe3+

Fe2O3

FeO



Polyatomic ions are ions that are made up of
more than one atom.

Ammonium: NH4+

Nitrite: NO2-

Nitrate: NO3-

Hydroxide: OH-

Hypochlorite: ClO-

Chlorite: ClO2-

Chlorate: ClO3-

Perchlorate: ClO4-

Carbonate: CO32-

Sulfite: SO32-

Sulfate: SO42-

Peroxide: O22-

PO43-

NH4Cl

Fe(NO3)3


TiBr3
Pb(SO4)2

Chromium (VI)
Phosphate

Tin (II) Nitrate

Cobalt (III) Oxide

Chromium (III)
Hydroxide






Barium Carbonate
Aluminum
Hydroxide
Copper (I) Sulfide
Lead (II) Phosphate
Zinc (II) Iodide
Chromium (III)
Sulfite

NH4Br

NaClO3

Fe2S3

AgNO3

CuF2

Ni(ClO)3

Ru3(PO4)4
Chapter 8

CO2

SO2

NF3

CCl4

What is the formula of Diarsneic trioxide?

Fluorine, and some other common elements,
usually exist as a molecule of F2.

Fluorine’s electron configuration is….

Fluorine’s structure is…

PH3

CCl4

HCl

SiH4

PBr3

NH3

NF3


To draw a lewis structure of a polyatomic ion
we first figure out how many valence
electrons we have, then add or subtract
electrons to account for the charge.
SO42-




A small group of molecules have have an odd
number of valence electrons and be unable to
form an octet around each atom.
NO2
An other group of molecules have expanded
octets.
SF6