1. 6.2 & 6.3 Molecules Key Concepts
How are atoms held together in a covalent bond?
What happens when atoms don’t share electrons equally?
What factors determine whether a molecule is polar?
How do attractions between polar molecules compare to attractions between nonpolar molecules?

2. Recall that ionic bonds form between _______________ charged ions
Which ion is the metal cation?
Which ion is the nonmetal anion?
Can two nonmetals form an ionic bond?
oppositely
Sodium (Na+)
Chloride (Cl-)
No, their charges will repel

3. Covalent Bonds
Two or more nonmetals, like two chlorine atoms, will ________________ electrons instead of transferring them
By sharing, the atoms remain ______________ and do _______ become ions…so they won’t repel
share
neutral
not

4. How many valence electrons does each chlorine atom have?
Cl Cl
Where can two chlorine atoms share electrons to make a bond?
7 (Group 7A)
Between the unpaired valence electrons

5. _______________ than ionic bonds
Covalent Bonds
A chemical bond in which two atoms share a pair of valence electrons is called a ______________ bond.
covalent
The attractions between the shared electrons and each ___________ is enough to hold the atoms together
_______________ than ionic bonds
nucleus
Weaker

6. There are several ways to show a covalent bond.
Covalent Bonds
There are several ways to show a covalent bond.
A pair of
dots is
replaced
by a _______
line
Show the orbitals that ___________
overlap

7. Molecules of Elements
A neutral group of atoms that are joined together by one or more covalent bonds is called a _________________
A chemical formula can also be used to describe the molecule…for example, a molecule of hydrogen is represented with the formula ________.
molecule H2

8. Many nonmetal elements exist as diatomic molecules.
Covalent Bonds
Many nonmetal elements exist as diatomic molecules.
Diatomic means “_______
__________”
two
atoms

9. “7 Up”…start with nitrogen, which has atomic number _____
Make a “7” and go “Up” to ___________ 7
hydrogen

10. Multiple Covalent Bonds
The hydrogen atoms share ______ pair of electrons…which is a called a ___________ bond
It is also possible for atoms to fill their outer energy levels by…
sharing ______ pairs of electrons, called a
_______________ bond
one
single
two
double 3 N N
triple

11. Nitrogen for example, is in Group 5A…so put 5 valence electrons around each nitrogen atom
N N
Each nitrogen needs _____ more valence electrons to meet the octet rule, so it will form three bonds 3

12. To name molecular compounds, simply…
write out the name of the first _________
follow it by the name of the second nonmetal with its ending changed to _____.
Add a ___________ to the name of each element to indicate _______ _________ atoms of element are present
nonmetal
-ide
prefix
how
many

13. The name for the molecule N2O3 is… ____________
Example:
The name for the molecule N2O3 is…
____________
# of atoms
prefix
dinitrogen
trioxide

14. Special Prefix Rules If only one atom of the _________ element is
listed, the prefix _________
is ___________
Example: the name for
NO2 is…
______________
Instead of mononitrogen dioxide
first
mono-
omitted
nitrogen
dioxide

15. Example: the name for NO is… _____________
Also, if the vowel combinations _____ or _____ appear next to each other in a name, the _______ vowel is omitted
Example: the name for NO is…
_____________
instead of nitrogen monooxide
o-o
a-o
first
nitrogen
monoxide

16. Practice! Name the following molecules… S2Cl2 _____________
SO _____________
N2O5 _____________
CO _____________
CO _____________
disulfur
dichloride
sulfur
trioxide
dinitrogen
pentoxide
carbon
dioxide
carbon
monoxide

17. More Practice! Write formulas for the following molecules…
Silicon dioxide _______
Iodine heptafluoride ______
Dinitrogen monoxide _____
carbon tetrachloride ______
SiO2
IF7
N2O
CCl4

18. What best describes a covalent bond?
Assessment Questions
What best describes a covalent bond?
An attraction between ions with opposite charges
The sharing of protons between neutral atoms
The sharing of electrons between neutral atoms
The sharing of neutrons between ions

19. Which “seven” nonmetals are diatomic?
Assessment Questions
Which “seven” nonmetals are diatomic? N2 O2 F2
Cl2
Br2 I2 H2

20. 3. Name the following molecular compound…IF7
Assessment Questions
3. Name the following molecular compound…IF7
Iodine heptafluoride