Chemical Bonds
Lewis Dot Structures
Chemical Names
Chemical Formulas
Acids
100
Ionic bonds (salts and crystals)
Formed between metals (loses electrons) and non-metals (gains electrons). Electrons are TRANSFERRED.
Electronegativity is more than 2.0
100
Octet rule
Every atom has 8 electrons in its highest energy level. WITH the exceptions of Hydrogen (2 e), Boron (6 e), and Main group elements in Period 3 can form bonds with more than 8 valence electrons.
100
Naming Ionic Compounds
The metal (cation) is listed before the non-metal (an-ion)
Subscripts do NOT affect the names of Ionic compounds.
The ending of the anions are dropped and replaced with the ending -ide.
AgCl = Silver Chloride
100
Writing Ionic chemical formulas
1. Write the symbols of the ions: Al O
2. Write the charge Al +3 O 2-
3. Cross the charges and multiply with original charges, then add to make sure they add up to 0. (3x-2) + (-2x3) = 0
4. Delete the charges and keep the new subscripts. Al2O3
100
Binary Acids
An acid (molecular compound) that consists of 2 elements, usually hydrogen and a halogen
200
Covalent bonds
are formed between nonmetals (electrons are shared between the atoms)
Electronegativity is less than 2.0
200
Steps for Ionic Compounds
1. Check that the bond is ionic and determine which atom is the cation (loses e) and which is the anion (gains e).
2. Write the symbol for the cation without any dots and draw the e diagram for the anion.
3. Enclose both in brackets and show each charge
200
Naming Ionic compounds with Polyatomic Ions
1. Name the Cation
2. Name the anion. The ending -ide is not necessary if the anion is a polyatomic ion.
Na2CO3 = Sodium Carbonate
200
Writing Ionic chemical formulas with Polyatomic Ions
Complete steps for regular Ionic chemical formulas but with the charges given on the formula sheet.
200
Oxyacids
Acids that contain hydrogen, oxygen, and a third element (Usually a nonmetal).
300
Metallic bonds
Based on the attraction between metal ions and free floating electrons.
Good conductors, malleable, ductile, shiny, high melting points.
The mobile electrons are what enable the metals to conduct electricity.
300
Steps for Covalent compounds
1. Write the Lewis dot structure for each atom
2. Determine the # of valence electrons available for bonding
3. Arrange into skeletal structure. (Carbon is always central, if not present atom with the least electronegativity is. Hydrogen is NEVER central)
4. Add unshared electrons to each nonmetal atom for a full octet
300
Naming Covalent Compounds
1. Identify the first element by its name and a corresponding prefix based on the subscript. (If it's one, a prefix isn't needed)
Identify the 2nd element and add the corresponding prefix. Drop the ending and add the ending -ide.
A2O5 = Diarsenic pentoxide
300
Writing Molecular formulas
1. The first half of the name gives you the element symbol and its subscript
2. The second half will give you the 2nd element symbol and its subscript
300
Naming a Binary Acid
1. Add the prefix Hydro-
2. Change the ending of the nonmetal to -ic
3. Add the word acid at the end.
The number of Hydrogens will be the same as the charge of the anion.
400
Properties of Ionic Bonds
High melting points, non-conductors as solids, but good conductors as liquids. Soluble in water but insoluble in alcohol.
400
MgCl2
400
Prefixes
1 = mono
2 - di
3 = tri
4 = tetra
5 = penta
6 = hexa
7 = hepta
8 = octa
9 = nona
10 = deca
400
Nomenclature
Uses Roman numerals to indicate a cation's charge as some transition metals form 2 or more cations with different charges.
400
Naming Oxyacids
1. If the polyatomic ion ends in "ate" add the suffix "ic" Sulfate = Sufuric
2. If the Polyatomic Ion ends in "ite" add the suffix "-"-ous"
3. Add the word acid to the ending
H2SO4 = Sulfuric Acid
500
Properties of Covalent bonds
Low melting points, Non-conductors in any phase, soluble in alcohol but insoluble in water.
500
HCl
500
S4O5
Tetrasulfur petoxide
500
Fe+3
Iron (III)
500
HCl
H2SO4
Hydrochloric acid (Binary)
Sulfuric acid (Oxyacid)