Ionic, Covalent bonding and naming of compounds
Valence Electrons are…?
The electrons responsible for the __________________ ______________________ of atoms, and are those in
the _______________ energy level.
Valence electrons - The ____ and ____electrons in the outer energy level or the _____________ occupied
energy level.
______________ electrons – are those in the energy levels below.
Keeping Track of Electrons
Atoms in the same column have the same outer __________________ configuration.
Have the same _________________ electrons.
The number of valence electrons are easily determined. It is the ______________ ___________ for a
representative element
Group 2A: Be, Mg, Ca, etc.
have _____ valence electrons
Electron Dot diagrams are…
X
A way of showing & keeping track of valence electrons.
Write the ____________ - it represents the nucleus and inner (core) electrons
Put one ___________for each ______________ electron (8 maximum)
They don’t __________ up until they have to (_____________ rule)
The _________________ Rule: in forming compounds, atoms tend to achieve a _____________ gas
configuration; _________ in the _____________ level is stable
Each noble gas (except He, which has 2) has 8 electrons in the outer level
Formation of Cations
Metals ___________ electrons to attain a ____________ gas configuration.
They make positive ions (________________)
If we look at the electron configuration, it makes sense to lose electrons:
Na 1s22s22p63s1 1 valence electron
Na1+ 1s22s22p6
This is a noble gas configuration with 8 electrons in the outer level.
Electron Dots For Cations
Metals will have few valence electrons (usually 3 or less); calcium has only 2 valence electrons
Let’s do Scandium, #21
- The electron configuration is: 1s22s22p63s23p64s23d1
Thus, it can lose 2e- (making it 2+), or lose 3e- (making 3+)
______________________
Let’s do Silver, element #47
Predicted configuration is: 1s22s22p63s23p64s23d104p65s24d9
Actual configuration is: 1s22s22p63s23p64s23d104p65s14d10
____________________ (can’t lose any more, charges of 3+ or greater are uncommon)
Silver did the best job it could, but it did not achieve a __________ Noble Gas configuration
Instead, it is called a “_________________________________________ configuration”
Electron Configurations: Anions
Nonmetals ____________electrons to attain noble gas configuration.
They make negative ions (___________________)
S = 1s22s22p63s23p4 = 6 valence electrons S2- = 1s22s22p63s23p6 = noble gas configuration.
___________ ions are ions from chlorine or other halogens that gain electrons
All atoms _____________to try and achieve a noble gas configuration.
Noble gases have ____ s and ______ p electrons.
8 valence electrons = already stable! This is the _________________ ______________ (8 in the outer level is
particularly stable).
Anions and cations are held together by opposite charges (+ and -)
Ionic compounds are called ____________.
Simplest ratio of elements in an ionic compound is called the _______________ _____________.
The bond is formed through the _______________ of electrons (lose and gain)
Electrons are transferred to ___________________ noble gas configuration.
Made from: a ______________ with an ________________ (or literally from a metal combining with a
nonmetal). All the electrons must be accounted for, and each atom will have a noble gas configuration (which is
stable).
Properties of Ionic Compounds
___________________________ solids.
High _____________________ points.
Ionic solids are ________________________. When melted, the ions can move around.
Melted ionic compounds ____________________. Dissolved in water, they also conduct (free to move in aqueous
solutions). Ionic solids are __________________.
Bonding in Metals
Metals hold on to their valence electrons ___________ ___________________.
Think of them as positive ions (cations) floating in a sea of __________________,
Electrons are free to move through the solid. Metals conduct ________________________.
Metals are ________________________ and ______________________. Both malleability and ductility
explained in terms of the _______________________ of the valence electrons
Naming Ionic Compounds
Atoms are electrically _________________.
Ions are atoms, or groups of atoms, with a charge
(__________________________________________________)
Naming cations
Stock system – uses ________________ numerals in parenthesis to indicate the numerical value
Classical method – uses root word with _________________ (-ous, -ic)
Cation - if the charge is always the same (like in the Group A metals) just write the name of the metal.
________________________ metals can have more than one type of charge.
Indicate their charge as a roman numeral in parenthesis after the name of the metal Predicting Ionic Charges
Some of the transition metals have only one ionic charge:
_____
______________ need to use roman numerals for these:
Silver is always 1+ (Ag1+) and Cadmium and Zinc are always 2+ (Cd2+ and Zn2+)
Naming Anions
Anions are always the ____________ _____________________.
Change the monatomic element ending to __________
Names and Formulas for Bases
A base is an ionic compound that produces _____________________ ions (OH1-) when dissolved in water (the
Arrhenius definition)
Bases are named the same way as other ionic compounds:
The name of the cation (which is a metal) is followed by the name of the anion (which will be hydroxide).
Names and Formulas for Bases
NaOH is ________________________ hydroxide
Ca(OH)2 is ________________________ hydroxide
To write the formula:
Write the symbol for the ___________________________________.
followed by the formula for the hydroxide ion (OH1-)
then use the ________________________________method to ______________ the charges.
Practice by writing the formula for the following:
Magnesium hydroxide
Iron (III) hydroxide
Zinc hydroxide
Writing Ionic Compound Formulas
Naming Ionic Compounds
1. Name the _________________ first, then anion
2. Monatomic cation = name of the element
Ca2+ = calcium ion
3. Monatomic anion = root + -ide
Cl- = chloride
CaCl2 = calcium chloride
Naming Ionic Compounds
some metals can form more than one charge (usually the transition metals)
use a Roman numeral in their name:
PbCl2 – use the anion to find the charge on the cation (chloride is always 1-)
Pb2+ is the lead (II) cation
PbCl2 = lead (II) chloride
Things to look for:
1) If cations have ( ), the number in parenthesis is their ___________________.
2) If anions end in -ide they are probably off the periodic table (Monoatomic)
3) If anion ends in -ate or –ite, then it is polyatomic
Practice by writing the formula or name as required…
Iron (II) Phosphate
Stannous Fluoride
Potassium Sulfide
Ammonium Chromate
MgSO4
FeCl3
of the cation