#1 Name the ions formed by these elements and
as anions or cations
a. selenium
selenide -2
anion
b. barium
barium ion +2
cation
phosphide ion -3
c. phosphorus
anion
#2How many electrons were lost or gained
to form these ions?
a. Fe3+
3 lost
b. O2-
2 gained
c. Cu+
1 lost
#3Key concept: Explain how the charges of Group A metal
and nonmetal ions are related to their positions in the
periodic table.
1
Group A elements
2
3 4 5 67
The charge on
the group A metals
is just the group
number. The charge
on the non-metals
is the group number
minus 8
8
4 Key concept: How are the charges of some
transition metal ions determined?
By how many electrons they lose. This can
sometimes be more than one number for a
given transition metal.(example Cr2+ and Cr3+)
5 Key concept: What are the usual endings
for the names of polyatomic ions?
-ite or -ate
examples:
#6 What are the charges on ions of
Group 1A, Group 3A(aluminum), and
Group 5A?
#7 How does a polyatomic anion differ
from a monatomic anion?
Chloride Cl-1
-2
Oxide
O
polyatomic anions
have more than one
Carbonate CO3-2atom, monatomic
Nitrite NO2-1
anions have only one atom
Hydroxide OH-1
Hydrogen sulfate HSO4
-1
Nitrate NO3-1
#8 Write the symbol for the ion of each
element. Classify the ion as an anion or
a cation, and name the ion.
a. potassium: K+ cation; potassium ion
b. oxygen: O2- anion; oxide ion
c. tin (2 electrons lost): Sn2+ cation; tin (II)
d. bromine Br- anion bromide ion
e. beryllium: Be2+ cation; beryllium ion
f. cobalt (3 electrons lost): Co3+ cation; cobalt (III)
#9 Write the symbol or formula (including
charges) for each of the following ions.
a. ammonium ion NH41+
b. tin (II) ion Sn2+
c. chromate ion CrO42d. nitrate ion
NO31-