Lewis Dot Diagrams for Compounds DO NOW: Draw the Lewis Dot Diagram for the following neutral atoms in their ground state: Hydrogen Carbon Oxygen HOMEWORK: In your Pearson Chemistry textbook, read pages 220-225 and complete # 1-3, 5, & 6 on page 225

Lewis Dot Diagrams for Compounds AIM: SWK… Matter/substances combine in predictable patterns. OBJECTIVE: SWBAT… Draw Lewis Dot Diagrams for molecular compounds. In Pearson Chemistry textbook, read pages 220-225 and complete # 1-3, 5, & 6 on page 225 =

Lewis Dot Diagrams for Compounds Recall the relationship between the electron configuration for an element, and the Lewis dot diagram for the element.

Lewis Dot Diagrams for Compounds In a Lewis dot diagram for an element, the elemental symbol represents the kernel of the atom, and the dots represent the electrons of the valence shell. Ne Kernel 

Lewis Dot Diagrams for Compounds In a Lewis dot diagram for an element, the elemental symbol represents the kernel of the atom, and the dots represent the electrons of the valence shell. Ne Valence Electrons 

Lewis Dot Diagrams for Compounds Each side of a Lewis dot diagram represents an orbital, which can hold up to two electrons. p1 orbital Ne p2 orbital s orbital p3 orbital

Lewis Dot Diagrams for Compounds Ex #1 How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of 1s2 2s2 2p4 ? First, we write the elemental symbol for the element, to represent the nucleus and all of the electrons except the valence shell. O

Lewis Dot Diagrams for Compounds Ex # 1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of 1s2 2s2 2p4 ? Next, we will draw dots to represent the valence electrons. Do you recall how to identify the valence shell? O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds Ex # 1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of is 1s2 2s2 2p4 ? Oxygen has six electrons in the valence shell. O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds Ex #1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of 1s2 2s2 2p4 ? The pair of s-electrons (2s2 in our example) are usually drawn on one side. O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds Ex #1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of 1s2 2s2 2p4 ? The p-electrons (there are 4 in our example) are placed one to a side, until they must double up. O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds Ex # 1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of 1s2 2s2 2p4 ? The p-electrons (there are 4 in our example) are placed one to a side, until they must double up. O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds Ex# 1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of is 1s2 2s2 2p4 ? The p-electrons (there are 4 in our example) are placed one to a side, until they must double up. O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds Ex# 1. How would we draw the Lewis dot diagram for oxygen (O), which has the electron configuration of is 1s2 2s2 2p4 ? The p-electrons (there are 4 in our example) are placed one to a side, until they must double up. O 1s2 2s2 2p4

Lewis Dot Diagrams for Compounds The orbitals that are not filled represent potential bonding sites. lone electrons O paired electrons 1s2 2s2 2p4 dot diagram for oxygen

Lewis Dot Diagrams for Compounds We would predict that this atom could make two single bonds or one double bond. bonding electrons O 1s2 2s2 2p4 dot diagram for oxygen

Lewis Dot Diagrams for Compounds If we know the molecular formula for the molecule, it is simply a matter of drawing the individual Lewis dot diagrams for each atom involved, and putting them together like the pieces of a puzzle.

Lewis Dot Diagrams for Compounds Hydrogen is in the first column of the periodic table, with an electron configuration of 1s1, so the Lewis dot diagram for hydrogen has one dot. Hydrogen: Of course, we will need two hydrogen atoms, because the formula for water is H2O.

Lewis Dot Diagrams for Compounds Oxygen, in column 16, has an electron configuration of 1s2 2s2 2p4, and 6 valence electrons. Hydrogen: Oxygen:

Lewis Dot Diagrams for Compounds Now, we can put the atoms together like pieces of a puzzle. Feel free to move electrons in the process. Hydrogen: Oxygen:

Lewis Dot Diagrams for Compounds Now, we can put the atoms together like pieces of a puzzle. Feel free to move electrons in the process. Hydrogen: Oxygen:

Lewis Dot Diagrams for Compounds Each single covalent bond represents a shared pair of electrons. Shared pair  Lewis dot diagram for water

Lewis Dot Diagrams for Compounds Remember, the atoms do not share the electrons equally. Shared pair  Lewis dot diagram for water

Lewis Dot Diagrams for Compounds Notice that oxygen now has a complete octet, with a valence shell like the noble gas neon. Lewis dot diagram for water

Lewis Dot Diagrams for Compounds The hydrogen atoms (which are small) each have two valence electrons, like the noble gas helium. Lewis dot diagram for water

Lewis Dot Diagrams for Compounds Also, notice that the shape of the Lewis dot diagram is similar to the shape of the actual molecule. Lewis dot diagram for water

Lewis Dot Diagrams for Compounds Let’s use this opportunity to review coordinate covalent bonds. Lewis dot diagram for water

Lewis Dot Diagrams for Compounds Coordinate covalent bonds, are formed when one atom provides both electrons for a shared pair. Lewis dot diagram for water

Lewis Dot Diagrams for Compounds A hydrogen ion (H+) is a bare proton. Lewis dot diagram for water

Lewis Dot Diagrams for Compounds It is so reactive that it can attach itself to the oxygen atom in water and force it to share a pair of electrons, even though it comes empty handed! Coordinate covalent bond

Lewis Dot Diagrams for Compounds The result of this interaction is the hydronium (H3O+) ion. + Lewis dot diagram for hydronium ion.

Lewis Dot Diagrams for Compounds Classwork: In the Prentice Hall workbook (red & blue) complete Section 8.2, pg 71-72 Homework: In Pearson Chemistry textbook, read pages 220-225 and complete # 1-3, 5, & 6 on page 225

Lewis Dot Diagrams for Compounds DO NOW: Draw the Lewis Dot Diagram for: Nitrogen trihydride Carbon dioxide AIM: SWK… Matter/substances combine in predictable patterns. OBJECTIVE: SWBAT… Draw Lewis Dot Diagrams for ionic compounds.

Lewis Dot Diagrams for Compounds Hint: Carbon dioxide has two double covalent bonds. Carbon: Oxygen: Carbon dioxide:

Lewis Dot Diagrams for Compounds HOMEWORK: In Pearson Chemistry textbook, read pages 226- 238, then complete # 11- 13, 16 & 20 on page 238 =

Lewis Dot Diagrams for Compounds Sodium chloride (NaCl) is an ionic compound, as a check of the electronegativies of the elements involved will show. The first thing we need to do is find the proper Lewis dot diagrams for the ions involved.

Lewis Dot Diagrams for Compounds Neutral sodium has an electron configuration of 1s2 2s2 2p6 3s1. This means that it has one valence electron, and a Lewis dot diagram as shown below. Na

Lewis Dot Diagrams for Compounds Recall also, the relationship between the oxidation number for an element, and the Lewis dot diagram for the element.

Lewis Dot Diagrams for Compounds Sodium has an oxidation number of +1, which means that it forms a +1 ion by giving up its one valence electron. Na 1s2 2s2 2p6 3s1

Lewis Dot Diagrams for Compounds This leaves the sodium (Na+) ion, with 8 valence electrons, since the second energy level is now its valence shell. + Na 1s2 2s2 2p6

Lewis Dot Diagrams for Compounds Notice that this configuration leaves the sodium ion with no lone electrons to form covalent bonds with. + Na 1s2 2s2 2p6

Lewis Dot Diagrams for Compounds Next, we look at neutral chlorine, which has an electron configuration of 1s2 2s2 2p6 3s2 2p5. This means that it has seven valence electrons, and a Lewis dot diagram as shown below. Cl

Lewis Dot Diagrams for Compounds With its one available bonding electron, a neutral chlorine will often form a covalent bond with another neutral atom to form the diatomic chlorine molecule, Cl2, as will all diatomic atoms. Cl

Lewis Dot Diagrams for Compounds However, in the case of ionic compounds, chlorine will become an ion. Chlorine has an oxidation number of –1, meaning that it gains one electron to become the chloride ion. - Cl

Lewis Dot Diagrams for Compounds Now, we simply write the Lewis dot diagrams of each element next to each other. Be careful not to make it look like the electron clouds overlap with each other.

Lewis Dot Diagrams for Compounds In order to make the fact that the two electron clouds don’t overlap more obvious, brackets are sometime put around ions, as shown below. + -

Lewis Dot Diagrams for Compounds Example 3. Potassium reacts with bromine to form potassium bromide. Draw the proper Lewis dot diagram for this product. Hint: Check oxidation numbers, and electronegativities!

Lewis Dot Diagrams for Compounds Example 3. Potassium reacts with bromine to form potassium bromide. Draw the proper Lewis dot diagram for this product. Potassium ion (K+): Bromide ion (Br-): Potassium bromide (KBr):

Lewis Dot Diagrams for Compounds Example 5. Zinc reacts with iodine to produce zinc iodide. Draw the proper Lewis dot diagram for this product. Hint: Check oxidation numbers, and electronegativities!

Lewis Dot Diagrams for Compounds Example 5. Zinc reacts with iodine to produce zinc iodide. Draw the proper Lewis dot diagram for this product. Zinc: Iodide: Zinc iodide (ZnI2):

Lewis Dot Diagrams for Compounds Pre-work video for visual learning if baseline expectations were met. Classwork: In the Prentice Hall workbook (red & blue) complete Section 7.2, pg 61-62 HOMEWORK: In Pearson Chemistry textbook, read pages 226- 238, then complete # 11- 13, 16 & 20 on page 238

Lewis Dot Diagrams for Compounds Classwork: In the Prentice Hall workbook (red & blue) complete Section 7.2, pg 61-62 HOMEWORK: In Pearson Chemistry textbook, read pages 226- 238, then complete # 11- 13, 16 & 20 on page 238