1. Chapter 12, section 1 Electrons and Chemical Bonding

2. Bell Work 12-1-15 When elements form mixtures, the elements A. A. keep their original properties. B. B. react to form a new substance with new properties. C. C. combine in a specific mass ratio. D. D. always change their physical state.

3. Bell Work 12-1-15 When elements form mixtures, the elements A. A. keep their original properties. B. B. react to form a new substance with new properties. C. C. combine in a specific mass ratio. D. D. always change their physical state.

4. Student Learning Objectives:  SPI 0807.9.1- Recognize that all matter consists of atoms.  SPI 0807.9.4 - Differentiate between a mixture and a compound.  SPI 0807.9.9 - Use the periodic table to determine the properties of an element. Describe chemical bonding. Describe chemical bonding. Identify the number of valence electrons in an atom. Identify the number of valence electrons in an atom.TOC: # Ch 12, section 1 Notes # Valence Electrons worksheet HW: Friday- Element #25-36 Quiz

5. Electrons and Chemical Bonding Video

6.  Chemical bonding is the joining of atoms to form new substances.  An interaction that holds two atoms together is called a chemical bond. When chemical bonds form, electrons are shared or transferred.

7. 3 Types of Chemical Bonds (write at the bottom of your notes)  Ionic Bonds: atoms gain or lose an electron and form ions (metals & nonmetals) NaCl  Covalent Bonds: sharing electron pairs between 2 nonmetals  Metallic Bonds: attraction between closely packed metals.

8.  The number of electrons in an atom can be determined from the atomic number of the element.  Electrons in an atom are organized in energy levels: 1 st – 2; 2 nd – 8; 3 rd – 18.

9.  Valence electrons are the number of electrons on the outermost (last) energy level  You can use the periodic table to determine the number of valence electrons for atoms of some elements

11.  The number of electrons in the valence level of an atom determine whether an atom will form bonds.  Atoms that have 8 electrons in their valence level do not usually form bonds. The outermost energy level is considered to be full if it contains 8 electrons.

12.  An atom that has fewer than 8 valence electrons is more likely to form bonds than at atom that has 8 valence electrons is. Atoms bond by gaining & losing electrons or sharing electrons to have a filled outermost energy level.

13. Activity: Move around the room!

14. Elbow Partner: Science Showdown (earn 10 house points) 1. Which of the following atoms do not usually form bonds? a. Calcium b. Neon c. Hydrogen d. Oxygen 2. When bonding occurs, the joining of two atoms will form a _______ _____________. 3. How can an atom that has 5 valence electrons achieve a full set of valence electrons? 4. Identify the number of valence electrons in a barium atom. Justify!

15. Check! 1. Which of the following atoms do not usually form bonds? a. Calcium b. Neon c. Hydrogen d. Oxygen 2. When bonding occurs, the joining of two atoms will form a chemical bonds or new substance. 3. How can an atom that has 5 valence electrons achieve a full set of valence electrons? They will share or gain 3 electrons. 4. Identify the number of valence electrons in a barium atom. A barium atom has 2 valence electrons. It’s a noble gas!

16. Valence Electrons Color each Group: 1. Group 1 – red 2. Group 2 – blue 3. Group 13 – yellow 4. Group 14 – brown 5. Group 15 – orange 6. Group 16 – violet 7. Group 17 – green 8. Group 18 – light blue Label the following groups: Alkali Metals Alkali Metals Alkaline Earth Metal Alkaline Earth Metal Transition Metals Transition Metals Halogens Halogens Noble Gases Noble Gases

17. Exit Ticket Look at the model. How many valence electrons are in the Nitrogen atom? Justify your answer.

18. Exit Ticket There are 5 valence electrons because there are 5 in the outermost shell.