atoms want 8ve- to be stable “happy”
DESCRIPTION
Atoms want 8ve- to be stable “happy”. Chemical Bonds / Formulas. Atoms bond to become stable or “happy” – octet rule (full valence shell) When they bond they form compounds. Each compound has a special formula Subscripts show how many of each element is in the compound. FORMULAS. - PowerPoint PPT PresentationTRANSCRIPT
Atoms want 8ve- to be stable “happy”
Chemical Bonds / Formulas Atoms bond to become stable or
“happy” – octet rule (full valence shell) When they bond they form
compounds. Each compound has a special
formula Subscripts show how many of each
element is in the compound
FORMULASMgCl2
The subscript is the number at the bottom of a formula.
There is 1- Mg & 2 – Cl Never use 1 as a subscript!
IONIC BONDbond formed between
two ions by the transfer of electrons
Ions Atom that gains or loses electrons
to become stable “happy” Cation: loses e- to form (+)
charged ion Anion: gains e- to form (-)
charged ion
Formation of Ions from Metals
Ionic compounds result when metals react with nonmetals
Metals lose electrons to form a positive charge Nonmetals gain electrons to form a negative
charge
Metals: Nonmetals: Na+ N -3
Ca+2 S -2
Al+3 Br -
IONIC BONDS Bonds form from the (+) & (-)
charges. Form a network of ions. – very
strong bonds. Conduct electricity when
melted or dissolved in water.
Writing Ionic Formulas – binaryRepresentative metals
Calcium & oxygen
Write the metal ion Ca +2
Write the nonmetal ion O -2
If charges cancel – ratio is 1:1 ( 1 of each)
CaO
Magnesium & chlorine
Write the metal ion Mg +2
Write the nonmetal ion Cl -
If charges DO NOT cancel – drop & swap
MgCl2
Writing Ionic Formulas – binaryTransition metals
Ion charges change – an element can have more than one ion charge
The charge is given as a ROMAN NUMERALEx: Iron (II) Fe+2 / Iron (III) Fe+3
Gold (I) Au + / Gold (III) Au+3
You will never have to memorize all the charges each transition metal forms – the charges will be given to you !!!!!
Practice Magnesium & iodine
Strontium & bromine
Barium & nitrogen
Aluminum & phosphorus
Naming Ionic Formula - binary Representative Metals
Name the metalChange the ending of the
nonmetal to – ide
MgCl2 - magnesium chlorideAlP - aluminum phosphide
Cl – chloride C - carbideF – flouride Se - selenideI – iodide N – nitrideP – phosphide S – sulfideBr – bromide O – oxide
Transition MetalsName the metal & Include the
charge using a Roman Numeral
Ex: Iron (II) Fe+2 / Iron (III) Fe+3
Gold (I) Au + / Gold (III) Au+3
Change the ending of the nonmetal ending to –ide
Fe +2 Cl - iron (II) chloride
Au + O -2 gold (I) oxide
Practice CaBr2
Na3N
BCl3
MgO
FeCl3
Ni3N
ZnO
FeS
Ternary Ionic Bonds – contain Polyatomic Ions
Polyatomic ion : a group of (covalently) bonded nonmetals that form a charge.
Act as a single ion in an ionic bond
Have special names that DO NOT CHANGE
You need to write down the polyatomic ions and their names on a sheet of paper and DO NOT LOSE IT!!!
You will use your list on all quizzes and tests!
AmmoniumNH4+
Acetate C2H3O2-
Hypochlorite ClO-
Chlorite ClO2-
Chlorate ClO3-
PerchlorateClO4-
Cyanide CN-
Hydroxide OH-
Nitrite NO2-
Nitrate NO3-
Bicarbonate/Hydrogen Carbonate HCO3-
Carbonate CO3-2
Chromate CrO4-2
Dichromate Cr2O7-2
Oxalate C2O4-2
Sulfate SO4-2
Sulfite SO3-2
Phosphite PO3-3
Phosphate PO4-3
Permanganate MnO4-
Peroxide O2-2
Writing Ionic Formulas - ternary Write the cation – all metals (only polyatomic cation
is ammonium: NH4+ )
Write the anion – all nonmetals and polyatomic ions
If charges cancel – 1:1 ratio
If charges DO NOT cancel – drop & swap You must use parenthesis if more than one
polyatomic ion is present
Practice cesium nitrate
barium sulfite
aluminum hydroxide
strontium phosphate
ammonium sulfide
Iron(III) chlorite
Zinc(II) nitrite
Gold(III) carbonate
Silver(I) phosphite
Copper(I) acetate
Naming ionic formulas - ternaryRepresentative metal Name the cation Use the same name
for the polyatomic ion
If the anion is a nonmetal – change the ending to -ide
Transition metal Name the metal and include
a ROMAN NUMERAL for the charge of the metal
Use the same name for the polyatomic ion
If the anion is a nonmetal – change the ending to -ide
Group 1 - Alkali Metals
reacts violently with water VERY reactive, one valence e-
to lose; +1 cation
Alkali metals http://www.youtube.com/watch?v=m55k
gyApYrY&safety_mode=true&persist_safety_mode=1
Group 2 - Alkaline Earth Metals
2 valence e-; +2 cation reactive
http://www.youtube.com/watch?v=m55kgyApYrY&safety_mode=true&persist_safety_mode=1
Transition Metals Groups 3-12 Ions charges change –
changes properties NOT REPRESENTATIVE!
Halogens -Group 17 -1 ions, highly reactive 7 valence e-
Noble Gases Group 18 unreactive, 8 valence e- do not form ions exist as single atoms,
don’t bond - inert
COVALENT BONDbond formed by the sharing of electrons
Covalent Compounds
Covalent compounds result when nonmetals react with nonmetals
Both nonmetals share their valence electrons to be happy – Octet Rule
Examples:CO2 SCl2
H2O CH4
Naming Covalent formulas Use prefixes to show the # of atoms of each
element in a covalent compound 1 – mono 6 - hexa 2 – di 7 - hepta 3 – tri 8- octa 4 – tetra 9 - nona 5 – penta 10 – deca
1st element – use prefixes only of the # of atoms is greater than 1
2nd element – use prefixes; change ending to – ide
Practice CO2
N3F8
Se4Br9
S7O
tetraselenium nonabromide
trinitrogen octaflouride
heptasulfur monoxide
carbon dioxide
Writing Covalent formulas Use the prefix to identify how many of each
nonmetal atoms are in each molecule The prefix becomes the subscript.
Carbon Tetrahydride Disulfur Hexachloride○ CH4 S2Cl6
1) Name the following covalent compounds:a) SiF4
b) N2S3
c) H3Br7
d) S5Br9
e) H2O
2) Write the formulas for the following covalent compounds:
a) diboron hexahydrideb) nitrogen tribromidec) sulfur hexachlorided) diphosphorus pentoxide