B onds between atoms are created when electrons are paired up by being transferred or shared. Atoms tend to form bonds that will allow it to obtain a full valence shell. Chemical Bonds

Two Types of Chemical Bonds: Ionic BondsCovalent Bonds -Electrons are transferred from one atom to another -Electrons are shared between atoms. - Usually occurs between a metal and nonmetal - Usually occurs between two nonmetals

Compounds Compounds are formed when two or more kinds of atoms are bound together chemically. Compound can be either ionic or covalent. Examples:

Why do these bonds occur? Remember: In a neutral atom the number of protons and neutrons are equal but the atom might be unhappy because it does not have a complete outer shell of electrons(8 electrons). All atoms want to be happy like the Nobel gases!!!!! How can atoms be happy? -By creating either an ionic or covalent bond. -If they create an ionic bond they either gain or lose an electron. -Positive ion form by losing an electron -Negative ion form by gaining an electron

Groups turning Ionic... Positive Ions (cation) Group 1Loses 1 electronIon with a +1 Charge Group 2Loses 2 electronsIon with a +2 Charge Group 13Loses 3 electronsIon with a +3 Charge Negative Ions (anion) Group 15Gains 3 electronsIon with a -3 charge Group 16Gains 2 electronsIon with a -2 charge Group 17Gains 1 electronIons with a -1 charge

Prefixnumber indicated mono-1 di-2 tri-3 tetra-4 penta-5 hexa-6 hepta-7 octa-8 nona-9 deca-10 Naming Binary Covalent Compounds

FormulaNames N2F6N2F6 Dinitrogen Hexafluoride CO 2 SiF 4 CBr 4 NCl 3 P2S3P2S3 CO NO 2 SF 2 PF 5 SO 2 NO CCl 4 P2O5P2O5 Examples :

Naming Binary Ionic Compounds Rules 1. The Cation (positive ion) is named first, the Anion second. 2. Monoatomic Cations take the element name Na + --> Sodium Ca 2+ --> Calcium 3. Monoatomic Anions take the elements name and ends with "-ide" Cl - --> Chloride NaCl --> Sodium Chloride Li 3 N --> Lithium Nitride Note** Greek prefixes are not used to indicate the number of atoms of each element in the formula unit for the compound (e.g., Na 2 O is named "sodium oxide" not "disodium oxide", or "disodium monoxide").

FormulaNameFormulaName a. Li 2 OLithium Oxiden. K 2 O b. CsClo. RbI c. MgS p. Mg 3 N 2 d. CaBr 2 q. Ca 3 P 2 e. BaI 2 r. Al 2 S 3 f. KHs. Ag 2 O g. Na 2 St. NaH h. AlNu. CaO i. AgFv. Na 2 S j. ZnOw. LiI k. CdI 2 x. CdS l. BaSy. ZnCl 2 m. LiClz. CsI Examples :

Naming Ionic Compounds using Roman Numerals (The Stock System of Naming) How do we name compounds when the cation of variable charge is involved? Some elements have more then one oxidation number and when naming a compound these must be identified. Roman numerals are shown after the cation in parenthesis( ) to indicate the oxidation number. To determine what the oxidation number is, you must use the anion (negative ion) to determine what the positive oxidation number is.

Example- Pb(NO 3 ) 4 write the name "lead nitrate". Since lead has more than one oxidation state we must figure out which lead we have. Since each nitrate (4 of them) has a 1- charge, the Pb must be 4+. So our roman numeral will be (IV). Pb(NO 3 ) 4 is named "lead(IV) nitrate" FormulaNameFormulaName FeCl 2 iron (II) chlorideSnCl 4 CoBr 3 FeP MnO 2 Hg 2 S NiBr 2 PbO HgOAuI CuF 2 SnS 2 CuI FeBr 3 SnBr 2 Cr 2 O 3 Au 3 P CoS Cr 2 S 3 MnI 2 NiBrNiS FeSPbO 2 PbCl 4 Mn 2 O 5

II.Nonbinary Ionic compounds (Use of Polyatomic Ions) Nonbinary means more than two different elements Step 1First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOHFe(NO 3 ) 3 Fe(SO 4 ) 2 Zn(C 2 H 3 O 2 ) 2

FormulaNameFormulaName NH 4 + AmmoniumO 2 2- Peroxide C2H3O2-C2H3O2- AcetateNO 3 - Nitrate CO 3 2- CarbonateNO 2 - Nitrite HCO 3 1- Hydorgen carbonate SO 4 2- Sulfate ClO 4 - PerchlorateSO 3 2- Sulfite ClO 3 - ChloratePO 4 3- Phosphate ClO 2 - ChloritePO 3 3- Phosphite ClO - HypochloriteCrO 4 2- Chromate CN - CyanideCr 2 O 7 2- Dichromate OH - HydroxideMnO 4 1- Permanganate Memorized Polyatomic Ion List

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOHFe(NO 3 ) 3 Fe(SO 4 ) 2 Zn(C 2 H 3 O 2 ) 2 Sodium hydroxide CO

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOHFe(NO 3 ) 3 Fe(SO 4 ) 2 Zn(C 2 H 3 O 2 ) 2 Sodium hydroxide Iron(III) nitrate

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOHFe(NO 3 ) 3 Fe(SO 4 ) 2 Zn(C 2 H 3 O 2 ) 2 Sodium hydroxide Iron(III) nitrate Iron(II) sulfate

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOHFe(NO 3 ) 3 Fe(SO 4 ) 2 Zn(C 2 H 3 O 2 ) 2 Sodium hydroxide Iron(III) nitrate Iron(II) sulfate Zinc acetate

NOMENCLATURE COVALENT BONDS (non-metal with non- metal) IONIC BONDS (metal with non-metal) POLYATOMIC ION (more than 2 elements in the compound) Rules: Use pre-fixes (mono-, di-, tri-, tetra-, penta-, etc…) Second element ends with the suffix “-ide) Rules: Find polyatomic ion on the cheat sheet. If the polyatomic ion is listed first, then the second element ends with the suffix “-ide) If the polyatomic ion is listed last, then simply name the first element. Rules: No pre-fixes! Second element ends with the suffix “-ide) If there is a TRANSITION METAL (groups 3-12) present, then use roman numerals (I, II, III, IV, V)

Balancing Chemical Equations Recall: The law of Conservation of Matter (mass). Matter can not be created or destroyed only changed. A chemical equation is a way to show matter being changed from one compound to another. For example: H + O > H O This equations show when hydrogen and oxygen combine it makes water. But look closer.... In the first half of the equation you have one hydrogen and one oxygen and in the second you have two hydrogen and one oxygen. You must balance this equation due to the law of conservation of matter. With the equation the way it is, you are saying that you created another hydrogen and you can not create matter. 2H + O-----> H O Now it is Balanced!!! Two hydrogen on each side and one oxygen on each side. 2 2

4 Types of Chemical Reactions 1. Single Replacement Reaction - Occurs when one element replaces another element in a compound. A + BC -----> B +AC 2. Double Replacement Reaction - Occurs when cations of two compounds switch places. AB + CD ----> CB + AD 3. Decomposition Reaction -Occurs when a single compound breaks down into simpler compounds. AB -----> A + B 4. Synthesis Reaction -Occurs when two of more substances combine to form a single substance. A + B ----> AB