Ionic--Covalent-and-Metallic-Bonding - Copy.pptx

chemical bonding concept

1. CHEMICAL BONDING Grade 10 -(chapter 2)

2. CHEMICAL BONDING Grade 10 -(chapter 2) Learning objective:::: What is a chemical bond? Why do atoms form chemical bond? How are the chemical bonds formed? Types of chemical bonds? Properties of each type of chemical bonding..

3. CHEMICAL BONDING Grade 10 -(chapter 2) Prior knowledge check::: Periodic table Metals and non-metals Noble gases Electronic configuration Octet rule

4. Electron Configuration 1 st level = max 2 electrons 2 nd level = max 8 electrons 3 rd level = max 8 electrons Start filling from the inside out. You cannot move up until a level is filled.

5. Why do Atoms React? The most stable arrangement of electrons in an atom is to have either a filled valence shell or to have 8 valence electrons (octet rule). Atoms obtain this stable electron arrangement by sharing, gaining or losing electrons – which is what creates chemical bonds. To get a full outer shell of electrons!

6. Types of Chemical Bonds There are three major types of chemical bonds: ionic bonding covalent bonding metallic bonding The type of bond formed depends on the ionization energy and electronegativity of the atoms involved

7. The Ionic Bond When an atom with a high EN is placed near an atom with a low IE, the first atom may “steal” an electron from the second atom. The atom that gives up the electron becomes a positively charged  cation , and the atom that gains the electron becomes a negatively charged  anion . An ionic bond  is the “electrostatic” attraction formed between the oppositely charged cation and anion. Properties of Ionic Compounds Ionic Bonding Definite crystalline structure High melting points Brittle as solids Most dissolve in water Conduct electricity  only  when in the molten state or when dissolved in water .

8. Ionic bonding

9. Sodium and chlorine

10. Covalent bond The electrostatic force of attraction between the nuclei of bonded atoms and the shared pair of electrons + + Shared pair or bonding electrons Covalent bond forms when pairs of electrons are shared by atoms. The shared electrons ( bonding electrons ) lie in the space between the atoms.

11. Covalent Bonds

12. 2. Covalent bonds- Two atoms share one or more pairs of outer-shell electrons. Oxygen Atom Oxygen Atom Oxygen Molecule (O 2 )

13. Drawing ion ic compounds using Lewis Dot Structures Symbol represents the KERNEL of the atom (nucleus and inner e-) dots represent valence e -

14. NaCl This is the finished Lewis Dot Structure [Na] + [ Cl ] - How did we get here?

15. Step 1 after checking that it is IONIC Determine which atom will be the + ion Determine which atom will be the - ion Step 2 Write the symbol for the + ion first. NO DOTS Draw the e- dot diagram for the – ion COMPLETE outer shell Step 3 Enclose both in brackets and show each charge

16. Draw the Lewis Diagrams LiF MgO CaCl 2 K 2 S