1. Physical Science Chapter 6 Chemical Bonds

2. Bonding Chapter 6 is about different types of atomic bonding Forces of attraction is the key to this bonding The physical properties of elements is key to the different types of bonds

3. Bonding

4. Draw the electron configuration of the elements neon and sodium

5. What do you notice about the Valence electrons and the energy level of each element?

6. Stable Electron Configurations When the highest occupied energy level of an atom is filled with electrons, the atom is stable and not likely to react

7. Ionic Bonds Elements without complete sets of valence electrons tend to react They react to try to achieve the stability of a full energy level…like the noble gases

8. Transfer of Electrons Look at the electron dot diagrams for sodium and chlorine What do you think these elements will want to do?

9. Atomic Chemical Reaction When sodium and chlorine react: An electron is transferred from each sodium atom to a chlorine atom. Now each atom is more stable

10. When an atom gains or loses an electron, the protons and electrons are no longer equal and the atom is not neutral. An atom with a positive or negative charge is an ion

11. Notice the positive and negative charge on the new sodium and chlorine atoms

12. Charge An ion with a negative charge is an anion. Chlorine in NaCl is an anion…Cl - It is negative because it has one more electron than protons, thus a charge of 1- Anions are written using a part of the elemental name and the suffix ide. – chloride

13. Our new sodium ion, because it lost an electron now has more protons than electrons, making it positive or 1+ – Na + Cations are named just using the elemental name, sodium

14. Chemical Bonds A chemical bond is what holds atoms or ions together Ionic bonds are what holds cations and anions together – Ionic bond forms when electrons are transferred from one atom to another

15. Chemical Bonds http://www.youtube.com/watch?v=QXT4OVM 4vXI http://www.youtube.com/watch?v=QXT4OVM 4vXI

16. Ionization Energy The amount of energy used to remove an electron from an atom is ionization energy It varies form element to element The lower the ionization energy, the easier it is to remove an electron

18. Which element would it be easier to take an electron from, Magnesium or Calcium?

19. Ionic Compounds Compounds that contain ionic bonds are ionic compounds These can be represented by a chemical formula: – Notation that shows what elements a compound contains and the ratio of the atoms or ions of these elements in the compound: NaCl

20. + =