Molecules, Compounds & Ions
To understand chemical combinations
Molecule
Recall:
 A type of a _____________________________
 A group of atoms that are _______________________ joined together to become “happy”
 For example, water (_________)
Becoming Happy…
Why join with other atoms?
 To ____________ their valence orbitals with ___ electrons
 A happy element is a ___________________________________
 To fill orbitals, atoms __________ / ___________ / ______________ electrons
Forming Compounds
All atoms / elements dream of being happy
 Like to have their valence orbitals (outermost shells) completely filled with 8 electrons
Ways Atoms Make Molecules
Alloy – a _______________ and a _________________
Molecular Compound – a ___________________ and a _______________________
Diatomic Compound – 2 of the ______________________________________________
Ionic Compound – a _____________ and a _________________________
Molecular Compound




Made up of 2 or more non-metals, especially _________________ and ___________________
Form a covalent bond
Meaning they ____________ electrons
Example: H2O
Diatomic Compound




A molecule consisting of atoms of the same element
Form a _____________
There are 7:
H2, N2, O2, F2, Cl2, Br2, I2
Example H2 = ____________________________
Ionic Compound



Ionic compounds form when metal ______and a non-metal ______ group together
Form an ionic bond, and a ________________ compound
Opposite charges attract
Ions

Ion – an atom that has become charged by ________________ or _____________ electron(s)

Remember elements want to be stable (“happy”)
Ionic Charges

Atoms that lose electrons have a ________________________ ionic charge

Atoms that gain electrons have a ________________________ ionic charge
-
meaning protons and electrons are no longer equal numbers
Chemical Symbols
Recall
 Are the short form of chemical elements, like your initials (one or two letters)

Always a CAPITAL then a lowercase

Example: H, He, Li, Be, B, etc…

Example ScIEnCE would have ______ elements in it
Chemical Formulas

Combination of element symbols used to indicate which elements have chemically bonded together
and to tell us how many of them
1. The types of element symbols indicate what type of pure substance it is
- If there is only one element symbol, the substance is an element
- If there is more than one element symbol, the substance is a compound
2. The element symbols in the formula tell you the elements present in the substance
3. The subscripts (small numbers) tell you how many atoms of each element are in each molecule of
the substance
Interpreting Formulas
Example: Sodium Carbonate ~ Na2CO3
Step 1: Is it an element or compound?
Step 2: What elements are present?
Step 3: How many of each element?
INTERPRETING FORMULAS PRACTICE
Element
Na
O
C
Metal or
Non-metal?
Lose / Gain
/ Share
Electrons?
How many
Electrons
lost /
shared /
gained?
Metal
Non-Metal
Non-Metal
Lose
Gain
Share
1
2
4
Is the Ion
Positive or
Negative?
Positive
Negative
Positive /
Negative
Ion Made?
Na+1
O-2
C+/-4
Mg
S
Al
Si
P
Chemical
Formula
H 2O
N2
Ne
NaCl
C7H5N3O6
KNO3
O2
Li
Element or
Compound?
Element,
Molecular Compound,
Diatomic Compound
or Ionic Compound?
Compound
Molecular
Element
Element
Diatomic
Element
Compound
Ionic
Element(s)
Present?
How many
of each
element
present?
Hydrogen
Oxygen
Nitrogen
Neon
Sodium
Chlorine
H = 2
O = 1
N = 2
Ne = 1
Na = 1
Cl = 1
INTERPRETING FORMULAS ANSWERS
How many
Electrons lost
Ion
/ shared /
Made?
gained?
Metal or Non-metal?
Lose / Gain /
Share
Electrons?
Positive or
Negative Ionic
Charge?
Na
O
C
Metal
Non-Metal
Non-Metal
Lose
Gain
Share
Positive
Negative
Positive / Negative
1
2
4
Na+1
O-2
C+/-4
Mg
Metal
Lose
Positive
2
Mg+2
S
Non-metal
Gain
Negative
2
S—2
Al
Metal
Lose
Positive
3
Al+3
Si
Non-metal
Share
Positive / negative
4
Si+/-4
P
Non-metal
gain
negative
3
P-3
Element
Element or
Compound?
Element,
Molecular Compound,
Diatomic Compound
or Ionic Compound?
Element(s)
Present?
How many
of each
element
present?
Compound
Molecular
Hydrogen
Oxygen
Nitrogen
Neon
Sodium
Chlorine
H = 2
O = 1
N = 2
Ne = 1
Na = 1
Cl = 1
Element
Element
Diatomic
Element
NaCl
Compound
Ionic
C7H5N3O6
Compound
Molecular
Carbon / Hydrogen
Nitrogen / Oxygen
C=7/H=5
N=3/O=6
KNO3
Compound
Ionic
Potassium
Nitrogen / Oxygen
K=1
N=1/O=3
NH3
Compound
Molecular
Nitrogen
Hydrogen
N=1
H=3
O2
Element
Diatomic
Oxygen
O=2
Li
Element
element
lithium
Li = 1
Chemical
Formula
H 2O
N2
Ne