IONIC BONDING Valence Electrons Electrons in highest occupied energy level The Roman numeral at the top of the representative elements gives the number of valence electrons. LiBr MgCl 2 K 3 PO 4 SrS NaOH KI CaCl 2 IA IIA IIIAIVAVAVIAVIIA VIIIA H BeLi BCNOF He Ne

How many valence electrons do the following elements have? Be - Rb- P- Se- Cl- Ne-

Valence electrons of the following Be -2 Rb- 1 P-5 Se-6 Cl-7 Ne-8

Lewis Dot Structures Lewis Dot Structures are used to show valence electrons Lewis Dot Structures are used to show valence electronsNe P2 P5 S1 S2 P3 P6 Remember P sublevel has 3 orbitals P4 P Order of filling in electrons Let’s practice… Write Lewis dot structures for the following H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, S,, Cl NOTE: The symbol for the element stands for the nucleus & inner electrons

Pause- Check your answers with your teacher What do you notice happening as you go down any “A” family group?

On the following, 1-write the electron configuration 2- underline the valence shell 3-Write the Lewis Dot structure Magnesium- Mg Phosphorus- P Zinc-Zn Bromine- Br Tungsten (II) Uranium (II)

PAUSE TO CHECK ANSWERS WITH the goddess of wisdom

Octet Rule In 1916, Gilbert Lewis came up with the In 1916, Gilbert Lewis came up with the OCTET RULE “Atoms react by changing the number of electrons so as to acquire the STABLE configuration of a noble gas. How many valence electrons do each of the following noble gases have? He, Ne, Ar, Kr, Xe, Rn Write Lewis Dot Structures for each of the noble gases above In ionic bonding, metals give electrons and non-metals take electrons to become STABLE by mimicking a noble gas.

Atoms are electrically neutral. WHY? If an atom gives away electrons to try to have the same configuration as a noble gas it will have a positive charge. Ions with a positive charge are called CATIONS + * GIVE AWAY electrons *Are POSITIVE * Are made from METALS

Atoms that accept additional electrons are NEGATIVELY CHARGED. These are negative ions. Ions with a negative charge are called ANIONS ANIONS * ACCEPT electrons * Are NEGATIVE * Made from NON-METALS

The ionization (loss or gain of valence electrons) can be shown using an electron dot structure. Na * loss of valence e- Na e- ionization Mg loss of valence e- Mg e- ionization You try Al Check on the board your answer and apply this to anions. ****

Lewis Dot and Ion Symbols For the following write the Lewis Dot Structure and then write the ion symbol. The first two will be done for you. Na* - Na + S - S 2- MgF CaN KO AlCl

PAUSE to complete ion handout

Transition metals The metals can form ions with more than one charge. Since they are metals they form ________________, or _______ charged ions. For example, Copper can form a Cu + or a Cu 2+ ion. In order to know which ion we are dealing with, we use ROMAN NUMERALS to tell us the charge on the ion. In our example, Cu + is called Copper (I); and Cu 2+ is called Copper (II). Write the ion symbol for the following Tin (IV); Tin (II); Chromium (II); Chromium (III); Iron (II); Iron (III); Lead (II); Lead (IV)

IONIC COMPOUNDS A COMPOUND is when 2 or more elements are chemically bound to each other. A COMPOUND is when 2 or more elements are chemically bound to each other. An IONIC COMPOUND is formed between ions. An IONIC COMPOUND is formed between ions. An IONIC COMPOUND is formed between a positive and negative ion. An IONIC COMPOUND is formed between a positive and negative ion. A BINARY(2) ionic compound is formed between a metal and a non-metal. A BINARY(2) ionic compound is formed between a metal and a non-metal.

The BOND in the ionic compound is formed because opposite charges ATTRACT. Once those positive and negative ions are formed due to the exchange of electrons, the ions are bound together and form a compound.

Turn to the board to get examples of ionic compounds.

Binary Ionic Compounds Are made from a metal and a non-metal. Are made from a metal and a non-metal. Are made from a positive ion and a negative ion Are made from a positive ion and a negative ion ALL IONIC COMPOUNDS are electrically NEUTRAL. ALL IONIC COMPOUNDS are electrically NEUTRAL. Therefore when forming compounds the # of positive charges from the cations must equal the # of negative charges from the anions. Therefore when forming compounds the # of positive charges from the cations must equal the # of negative charges from the anions.

Binary Ionic Compounds Cont. Example Example Na + and Cl 1- form a compound NaCl Na + and Cl 1- form a compound NaCl Only one ion of each is required because the 1+ charge on Na is balanced by the 1- charge on Cl. Only one ion of each is required because the 1+ charge on Na is balanced by the 1- charge on Cl. Mg 2+ and O 2- form a compound MgO ; charges are balanced. But, what if Na + forms a compound with O 2- ?

Binary ionic compounds cont. If Na + and O 2- form a compound, you just have to make sure the charges are balanced. An additional sodium ion is needed. If Na + and O 2- form a compound, you just have to make sure the charges are balanced. An additional sodium ion is needed. Na + with O 2- form a compound Na 2 O Na + with O 2- form a compound Na 2 O Na + Na + This compound requires 2 sodium ions for every 1 oxygen ion. Try Ca 2+ and F 1- Try Ca 2+ and F 1- What about Al 3+ and O 2- ? Try it. What about Al 3+ and O 2- ? Try it.

Naming Binary Ionic Compounds Recall the name of cations doesn’t change. A sodium ion is simply sodium. Recall the name of cations doesn’t change. A sodium ion is simply sodium. Recall the name of anions changes to Recall the name of anions changes to–ide. So, you simply name the cation (which always comes first) followed by the name of the anion with an –ide ending. EX: NaCl – sodium & chlorine becomes sodium chloride; MgO – magnesium & oxygen becomes magnesium oxide CaBr 2 – calcium & bromine becomes calcium bromide

Binary IONIC COMPOUNDS Your Turn Write the compound formula for the ionic compund formed from the pairs of ions below. Name each compound as well. 1) Na + and F 1- 2) Mg 2+ and S 2- 3) Al 3+ and P 3- 4) K + and S 2- 5) Ca 2+ and Cl 1- 6) Al 3+ and Se 2- 7)Cu 2+ and F 1- 8) Sn 4+ and Cl 1- 9) Cr 3+ and O 2- 10) Pb 4+ and O 2-

Pause for “The Criss-Cross Method” Demo

Answers to Binary Ionic Compounds 1)NaF sodium fluoride 2) MgS magnesium sulfide 3) AlP aluminum phosphide 4) K 2 S potassium sulfide 5) CaCl 2 calcium chloride 6) Al 2 Se 3 aluminum selenide 7) CuF 2 copper (II) fluoride 8) SnCl 4 Tin (IV) chloride 9) Cr 2 O 3 Chromium (III) oxide 10) PbO 2 Lead (IV) oxide

Polyatomic Ions Polyatomic ions Polyatomic ions “poly” means many; “atomic” refers to atoms “poly” means many; “atomic” refers to atoms A polyatomic ion is just an ion made of several atoms rather than just one as seen earlier. A polyatomic ion is just an ion made of several atoms rather than just one as seen earlier. Polyatomic ions are groups of atoms with a positive or negative charge Polyatomic ions are groups of atoms with a positive or negative charge Most polyatomic ions are ANIONS Most polyatomic ions are ANIONS

Polyatomic Ions cont. The names of most polyatomic ions end in –ite or –ate, rather than –ide as with single element ions. EXAMPLES: NO nitrateNO nitrite SO sulfateSO sulfite PO phosphatePO phosphite What do you notice about the difference in –ate ions and –ite ions of the same family?

Ternary compounds Ternary ionic compounds are just ionic compounds that have a polyatomic ion. Ternary ionic compounds are just ionic compounds that have a polyatomic ion. Just like binary compounds the charges must balance. Just like binary compounds the charges must balance. EX: Na + & NO 3 1- The charges are balanced so only one of each ion is needed. The formula is NaNO 3 and is named sodium nitrate EX: Na + & NO 3 1- The charges are balanced so only one of each ion is needed. The formula is NaNO 3 and is named sodium nitrate Na + & SO 3 2- To balance charges, 2 sodium ions are needed. The formula is Na 2 SO 3 and is named sodium sulfite Na + & SO 3 2- To balance charges, 2 sodium ions are needed. The formula is Na 2 SO 3 and is named sodium sulfite

Ternary Compounds Cont. It is important to note that the names of polyatomic ions do NOT change. Nitrate, nitrite, sulfate etc. tells you which ion you are dealing with. It is important to note that the names of polyatomic ions do NOT change. Nitrate, nitrite, sulfate etc. tells you which ion you are dealing with. Also polyatomic ion formulas DO NOT change. NO 3 for nitrate must stay NO 3 regardless, so what if you need 2 groups of NO 3 to form a compound? Also polyatomic ion formulas DO NOT change. NO 3 for nitrate must stay NO 3 regardless, so what if you need 2 groups of NO 3 to form a compound? IF more than one group of a polyatomic ion is needed to form a compound, parentheses are used. Continue for examples. IF more than one group of a polyatomic ion is needed to form a compound, parentheses are used. Continue for examples.

Examples of ternary compounds Mg 2+ & NO 3 1- Mg(NO 3 ) 2 Magnesium nitrate Al 3+ & ClO 4 1- Al(ClO 4 )aluminum chlorate Al 3+ & SO 3 2- Al 2 (SO 3 ) 3 aluminum sulfite You Try : Ca 2+ & ClO 3 1- Pb 4+ & PO 4 3- Cu 2+ & (NO 2 ) 1- Cr 3+ & OH 1-

Complete the compound writing worksheet