Bonding - Atoms interact (with their electrons) to form compounds. Sodium Chlorine

2 Three Kinds of Bonds:Ionic Covalent Metallic Metal gives up electrons to make opposites attract. The sharing of electrons creates a strong bond. All electrons are shared in a “sea of electrons.” Metal (+)Nonmetal (-) Nonmetal Metal electrons Metal

3 Independent Practice Fill in the the blanks C - Covalent M - Metallic I - Ionic

4 To understand how bonding works, we need to understand electrons. Proton Electron Neutron + + Positive Charge No Charge Negative Charge

5 Valence Electrons The electrons on the outer energy level of an atom How many valence electrons do each of these have?

6 3 Li Na Mg K Ca S Cl Ar Ne F Al Si P B C N O H Be He Do you remember what the atomic number represents? It is the number of protons & electrons.

7 1 H He Energy Level 1 2 electrons fit Fill in the periodic table on your paper. How many valence electrons does hydrogen have? How many valence electrons does helium have?

8 3 Li Ne F B C N O Be Energy Level 2 8 electrons fit: Fill in the periodic table on your paper. How many valence electrons do each of the elements above have?

9 11 Na Mg S Cl Ar Al Si P Energy Level 3 8 electrons fit Fill in the periodic table on your paper. How many valence electrons do each of the elements above have?

10 Look at the periodic table. Do you notice a pattern? What is it?

11 valence electrons You should have noticed that each column has the same number of valence electrons. This is true all the way down the periodic table:

12 But there is something you need to know about electrons and the energy levels where they live. Some are happier than others. You see, energy levels like to be FULL. 10 Ne Ar He Which other atoms are FULL? These are “HAPPY” atoms.

13 Everyone wants to be happy-- so, all atoms try to get happy. But alas, they cannot do it alone. They must find other atom friends to make them happy. Someone that understands you.Someone that understands you. One who is willing to give you what you need most -- a part of himself.One who is willing to give you what you need most -- a part of himself. But the right kind of friend is hard to find -- if you know what I mean.

14 More on electrons: Atoms get happy (stable) by filling up their outer shell of electrons. Atoms with 4 or more valence electrons will not give them up! No, and don’t ask again! Yes, is there anything else? Atoms with less than 4 valence electrons are very generous. Which columns on the periodic table will NOT give away electrons? Which columns on the periodic table will give away electrons? friend in need  Generous Friend

15 However this affects their charge…Remember normally: # of Protons (+) = Electrons (-) If the the blue atom gives up an electron, it becomes (+). If the yellow atom gives up an electron, it becomes (-). Even MORE about electrons: Have the same Lose -e makes + Gain -e makes - Generous friend helps a friend in need.

16 Because of this, we assign a group of elements an oxidation number. Compare this number to the valence electrons Write the oxidation numbers on your periodic table. H He BeBCNOF

17 Independent Practice Fill in the the chart on your paper.

18 Bonding Bonding An atom’s outer electron energy level is filled by either exchanging or sharing electrons. NaCl NH 3 Na Cl N H H H NHHHClNa

Sodium Chlorine Electrons either taken or given away + Opposites attract Ionic Bonds Metal to Nonmetal 19

20 Sodium Chlorine Sodium Chloride Sodium is happy at energy level 2. Chlorine is happy at energy level 3. Sodium gives Chlorine 1 electron. NaCl ClNa Ionic Bonds Metal to Nonmetal

21 NH 3 Ammonia NHHH Covalent non-metal + nonmetalHydrogen Hydrogen Hydrogen Nitrogen Energy level HAPPY or stable... Electrons are shared.

22 Metallic -e Ag + -e Share in a sea of electrons electrons metal

23 Independent Practice Fill in the the chart on your paper.

Mg +2 Cl -1 MgCl Oxidation Number Varies Mg +2 O -2 MgO 22= Fe +3 O -2 Fe 2 O 3 23 When you combine atoms, you use the oxidation numbers to help you figure out the ratio. Simply switch the oxidation number to get the correct subscript. Put the #s in lowest terms if necessary.

25 Independent Practice Fill in the the chart on your paper.

26 Polyatomic Compounds: Compounds that Act as a Unit Mg +2 PO Mg 3 (PO 4 ) Li +2 SO LiSO 4 22 Fe +3 NO 4 -2 Fe 2 (NO 4 ) 3 23 Note the ( ) on multiple polyatomic ions.

27 Independent Practice Fill in the the chart on your paper.

28 Naming Compounds Rules for naming binary (meaning 2 types of atoms) ionic compounds: 1. Write the name of the metal first. Example: KBr Potassium 2. Write the name of the nonmetal changing the ending to “ide.” Bromine Bromide

29 Independent Practice Fill in the blanks.

30 Naming Compounds Rules for naming binary ionic compounds: 1. Write the name of the metal first. Example: CuCl Copper 2. Write the name of the nonmetal changing the ending to “ide.” Chlorine Chloride 3. If the metal is a “transition metal,” the oxidation number varies. Therefore, to name the compound we must put the ionic charge in parentheses. For example: (I) because the oxidation of chlorine is 1. (Binary means 2 types of atoms.)

31 Independent Practice Fill in the blanks.

32 Naming Compounds Rules for naming polyatomic ionic compounds: 1. Write the name of the metal first. Example: K 2 SO 4 Potassium 2. Write the name of the polyatomic nonmetal from the chart. Sulfate Polyatomic

33 Naming Compounds Rules for naming polyatomic ionic compounds: 1. Use the chart above to name the metal. Example: NH 4 Cl Ammonium Ionic If the polyatomic ion is first, then: 2. Write the name of the nonmetal changing the ending to “ide.” Chloride

34 Review: Click below Take the quiz at the bottom of the page.