8. Monoatomic Ions
Mono means one.
When the metals in groups 1A, 2A and 3A lose
electrons, they form cations with positive
charges equal to their group number.
They keep their names and just put the word
“ion” after it.
Nonmetals tend to gain electrons to form anions.
The charge of any anion is determined by
subtracting 8 from their group number.
Elements in group 7A have a -1 charge and so
on.
Their names will have the ending –ide.
For example, oxide, nitride, phosphide….etc
9. Ions of Transition Metals
The metals of groups 1B-8B form more
than one cation with different charges.
The charges of the cations of many
transition metal ions must be determined
from the number of electrons lost.
To name these ions, a Roman numeral is
used in parentheses after the name of the
element.
For example, Fe+3 would be called iron(III).
10. Polyatomic Ions
Some ions, called polyatomic ions, are
composed of more than one atom.
The names of polyatomic ions end in –ite
or –ate.
There are three other ions that have
different endings cyanide, ammonium and
hydroxide
All ions with oxygen in them end with an –
ite or an –ate.
Refer to your polyatomic table for the
names and charges.
11. Let’s Practice!
Write the name for the following:
Ca+2
Fe+2
Cu+1
Li2C03
NH4+
NO3BrNH4NO3
I’M READY!!
12. ANSWERS!
Write the name for the following:
Ca+2
Li2C03
calcium ion
iron(II) ion
copper(I) ion
lithium carbonate
NH4+
ammonium ion
Fe+2
Cu+1
NO3-
nitrate ion
Br-
bromide ion
ammonium nitrate
NH4NO3
15. Writing Formulas for Ionic
Compounds
A binary compound is composed of two
elements and can be either ionic or molecular.
To name any binary ionic compound, place the
cation first and then the anion name.
To write a formula for a binary compound, write
the symbol of the cation and then the anion.
Add whatever subscripts are needed to balance
the charges.
BALANCING THE CHARGES IS
IMPORTANT!!!!
16. Balancing Charges Using the
Crossdown Method
Write the cation first with its charge.
Then write the anion with its charge.
The charge of one ion becomes the
subscript for the other ion.
You “cross” them down.
If the charges match, then no numbers are
needed.
Remember, each compound wants to have
a net charge of zero.
17. Let’s Practice!
Write the formulas for the following binary
compounds.
Barium sulfide
Calcium nitride
Lithium oxide
Copper(II) iodide
Iron(III) oxide
18. ANSWERS!!
Write the formulas for the following binary
compounds.
Barium sulfide
Calcium nitride
Lithium oxide
Copper(II) iodide
Iron(III) oxide
BaS
Ca3N2
Li2O
CuI2
Fe 2O3
19. Compounds with Polyatomic Ions
Write the symbol and charge for the
cation.
Write the polyatomic formula and the
charge.
Cross down the charges.
Remember, they must balance to zero.
Pretend the polyatomic ion is one atom.
If more than one polyatomic ion is needed,
put parentheses around the polyatomic
formula.
20. Let’s Practice!
Write the formulas for the following:
Calcium nitrate
Sodium carbonate
Calcium phosphate
21. ANSWERS!
Write the formulas for the following:
Calcium nitrate
Sodium carbonate
Calcium phosphate
Ca(NO 3)2
Na2CO3
Ca3(PO4)2
23. SUM IT UP!
Write the formula for:
Potassium sulfide
Calcium carbonate
24. Naming and Writing Formulas for
Covalent (Molecular) Compounds
The prefix in the name of the binary compound
tells how many atoms of each element are
present in the molecule. (see table 9.4)
The suffix for all the compounds is –ide.
Use the prefixes in the name to tell you the
subscript of each element in the formula.
Write the correct symbols and the appropriate
subscripts.
25. LET’S PRACTICE!
Write the names/formulas of the following
compounds.
CS2
Cl2O7
NI3
Carbon tetrabromide
Diphosphorus trioxide
26. ANSWERS
Write the names/formulas of the following
compounds.
CS2
Cl2O7
NI3
carbon disulfide
dichloride heptaoxide
nitrogen triiodide
Carbon tetrabromide
CBr4
Diphosphorus trioxide
P2O3
27.
28.
29.
30. Naming and Writing Formulas for
Acids
An acid is a compound that contains one or
more hydrogen atoms and produces hydrogen
ions when dissolved in water.
When the name of the anion ends in –ide, the
acid name begins with the prefix hydro- and has
the suffix –ic and ends in acid.
When the anion name ends in –ite the acid
name ends in –ous followed by acid.
When the anion name ends in –ate, the acid
name ends in –ic followed by acid.
31. LET’S PRACTICE!
Write the name/formula for the following
acids:
HBr
H2SO4
Hydrochloric acid
Carbonic acid
HNO2
If you don’t get this
right….I’m coming for your
SOUL!
32. The Laws of Definite and Multiple
Proportions
The law of definite proportions states that in any
sample of a chemical compound, the masses of
the elements are always in the same
proportions.
They will always combine in simple wholenumber ratios.
The law of multiple proportions states that
whenever two elements form more than one
compound, they will be in simple whole number
ratios.
34. Word Equations
Symbols to remember:
means yield or produces or makes, it’s like
an =sign in math
+ means add the compounds together
A triangle above the arrow, means heat is
added.
(s) means solid or precipitate, (aq) means
aqueous or dissolved in water, (g) means gas, (l)
means liquid.
Reactants must equal the products. No random
compounds!!
35. LET’S PRACTICE!
1.
Hydrogen gas and oxygen gas
combine to form liquid water.
2. Methane gas (CH4) and oxygen gas
combine to form carbon dioxide gas and
liquid water.
3. Solid Ammonium carbonate and
dissolved calcium nitrate are mixed
together. Dissolved Ammonium nitrate and
solid calcium carbonate are made.