1. Unit 2: Atoms Elements and Bonds
Lesson 4: Ionic and Covalent Bonds

2. Bell Work
What is an atom and what are the three parts of an atom and what are their charges?
What is a chemical formula? What information can you get from a chemical formula?
What are the two types of mixtures?
What is the difference between a compound and a mixture?

3. Today’s Agenda Bell Work Review This week’s Agenda Ionic Bond Notes
Review Questions

4. This Week’s Agenda Monday Tuesday Wednesday Thursday Friday
Notes on Ionic Bonds
Tuesday
Notes on Covalent Bonds
Wednesday
Quizziz to Review
Edpuzzle
Finish Up notes
Thursday
Quiz on Ionic and Covalent Bond
Review Worksheets
Friday
Mystery Friday (Depending on behavior)

5. SC Standards
Standard 7.P.2: The student will demonstrate an understanding of the structure and properties of matter and that matter is conserved as it undergoes changes.
7.P.2.A Conceptual Understanding: All substances are composed of one or more elements. Elements are pure substances which contain only one kind of atom. The periodic table organizes these elements based on similar properties. Compounds are substances composed of two or more elements. Chemical formulas can be used to describe compounds.
7.P.2A.4: Construct explanations for how compounds are classified as ionic (metal bonded to nonmetal) or covalent (nonmetals bonded together) using chemical formulas.
S.1A.6: Construct explanations of phenomena using (1) primary or secondary scientific evidence and models, (2) conclusions from scientific investigations, (3) predictions based on observations and measurements, or (4) data communicated in graphs, tables, or diagrams.

6. Today’s Objectives (SWBAT)
Construct explanations of how compounds are classified as ionic or covalent using chemical formulas.

7. Day 1
Ions and Ionic Bonds

8. What are Ions? Ion Happens Metals tend to LOSE Nonmetals tend to GAIN
Is an atom or group of atoms that had an electron change
Happens
When a neutral atom LOSES a valance electron
The atom will become positive
When a neutral atom GAINS a valance electron
The atom will be negative
Metals tend to LOSE
Nonmetals tend to GAIN

9. Common Ions Ions that are made from more than 1 atom
Some ions are made of several atoms
Polyatomic ions
Ions that are made from more than 1 atom
Are positive or negative

10. Ionic Bonds
Happens when atoms easily loose and electron and other gain an electron
Valence electrons are transferred from one atom to another
Example:
Na will lose an electron and become positive
Cl will gain an electron and become negative
Ionic Compounds
Made up of positive and negative ions
Positive ions will equal negative ions

11. Example

12. Ionic Chemical Formulas
A group of symbols that show the ratio of elements in a compound
If no subscript assume the number is 1
Cl looses 1 valence electrons, thus it takes 2 to make it a neutral compound
MgCl2
Magnesium will loose 2 electrons
Lets us know that there are 2 Cl atoms

13. Brain Break (Answer the following questions)
Take 5 minutes and answer these questions
What is an ion?
What are ionic bonds?
What is a chemical formula?

14. Naming Ionic Bonds Name of the positive ion comes first
The name of the negative ion come last

15. Properties of Ionic Compounds
Form hard brittle crystals that have high melting points
Conduct electricity when dissolved in water or melted
Ionic crystals
Form solids by building up repeating patterns of ions
Crystals: orderly 3-D arrangement of ions
Ions are attracted to ion of an opposite charge
High Melting Point
Take a lot of energy to break apart ion crystals
Melting point of NaCl is 801C

16. Day 1 Review Questions
An atom that loses a valance electron become a (positive/negative) ion. An atom that gains a valance electron becomes a (positive/negative) ion
Determine the number of atoms of each element in the chemical formula Na2S
Ionic bonds are strong enough to cause almost all compounds to be ______________ at room temperature.

17. Day 2
Covalent Bonds

18. Bell Work What are ions? How do they form What are ionic bonds?
Name 3 common ionic bonds

19. Covalent Bonds Molecule
Form between nonmetals
Share electrons
Electron Sharing
Attraction between shared electrons
Proton in nucleus of each atom hold the atoms together
Molecule
A neutral group of atoms joins by covalent bonds

20. Covalent Bonds
Carbon has 4 valence electrons (Remember what group Carbon is in)
Carbon can have 4 bonds
Hydrogen has 1 valence electron (remember what group Hydrogen is in)
It can only form 1 bond
Carbon and Hydrogen will share an electron

21. How Many Bonds Draw an electron dot diagram
Count number of valence electrons
Examples
H=1 valence electron=1 bond
C=4 valence electrons=4 bonds
O=6 valence electrons=2 bonds
Double Bonds
2 atoms share 2 pairs of electrons
Triple Bonds
2 atoms share 3 pairs of electrons

22. Different Bond Example

23. Brain Break (Take 5 minutes to answer these questions)
What is a covalent bond?
How is it different then an ionic bond?
How many bonds can you have in a covalent bond?

24. Properties of Molecular Compounds
Compounds made of molecules
Contains atoms that are covalently bonded together
Do not conduct electricity when melted or dissolved in water.
Have lower melting and boiling points
Do not contain charged particles
Weaker bonds then ionic
Table sugar melts at 190C table salt melts at 801C

25. Partially Charged Atoms of some elements have more pull then others
Unequal sharing of electrons causes covalently bonded atoms to have slight electric charges

26. Nonpolar and Polar Bonds
Each atom pulls on the electron the same
Electron are shared equally
Polar Bonds
When one atom have a slightly stronger pull on the electrons
The strong atom will be slightly negative
The weaker atom will be slightly positive

27. Van der Waals Forces Van der Waals Forces
Weak attraction between the slightly positive and negative charges
Higher melting and boiling point
Example
Water

28. Day 2 Review Draw an electron dot diagram for 1 iodine atoms
Water is an example of a(n) (ionic/molecular) compound.
When do molecular compounds form?
Sodium chloride is an example of a(n) (ionic/molecular) compound.
Ionic compounds form when…