1. Mt 2
Chemical Bonds

2. But first, let’s review
What do we call the smallest form of an element?
What does the Atomic Number of an element tell us?
How do we determine the number of electrons found on the outer ring?
What is the name of electrons that are found on the outer ring?
How do we determine the number of electron rings an element has?

3. How is the structure of an atom related to bonding?
The keys to answering that question is related to the
Number of Valence Electrons
Number of Electron Rings

4. How is the structure of an atom related to bonding?
Valence Electrons – the number of electrons that are in the outer ring of an atom
Electron Rings/orbitals – the number of rings or orbitals an atom has that can hold electrons

5. What is an atom? An atom is the smallest form of matter
Has an equal number of protons & electrons

6. What is an ion?
An ion is an atom that has either lost or gained electrons
Negative Ion:
Gained Electrons
Positive Ion:
Lost Electrons

7. What is an ion? Metals will lose electrons
Electrons lost is equal to number of Valence electrons
Example: Lithium 1 Valence Electron, Loses 1 electron
Nonmetals will gain electrons
Electrons gained will equal the number of electrons needed to equal 8
Example: Oxygen 6 Valence Electrons, Gains 2 electrons

8. Why do atoms want to form a Chemical Bond?
They want to become more STABLE
which means they want to be at a lower energy state
All Atoms want to have a FULL OUTER RING
The only elements that have a full outer shell are the Nobel Gases
Therefore, all elements want to look like Noble Gases, meaning they want their electron rings to be filled
Neon Atom
Nobel Gas
Lithium Atom

9. What do we call the product of a bond?
Atoms will form a Molecule or Compound when they bond

10. What is the Octet Rule?
When atoms form bonds, they follow the Octet Rule
Octet Rule
atoms tend to gain, lose or share electrons so as to have 8 electrons

11. C would like to
N would like to
O would like to
Gain 4 electrons
Gain 3 electrons
Gain 2 electrons

12. What are the rules of electron shells?
The 1st shell can hold up to 2 electrons, and each shell thereafter can hold up to 8 electrons.
Keep in mind that there are subshells that can also hold differing amounts of electrons.

14. What are the types of chemical bonds?
Ionic Bonds
Covalent Bonds
Metallic Bonds

15. What is an Ionic Bond?

16. What is an Ionic Bond? Examples Types of Elements Electron Activity:
A bond formed between a metal and a nonmetal that have become ions
Electron Activity:
Electrons are transferred from the metal to the nonmetal
Examples
NaCl, CaCl2, K2O

17. Review - What is an ion?
An ion is an atom that has either lost or gained electrons
Metals lose electrons to form Positive Ions
number of electrons are less than the number of protons
Nonmetals gain electrons to form Negative Ions
Number of electrons are more than the number of protons

19. What is a Covalent Bond?

20. What is a Covalent Bond? Types of Elements Electron Activity
A bond formed between Non-metals
Electron Activity
Electrons are SHARED between the nonmetals
They do not conduct electricity or heat at any state (solid, liquid, gas)
Examples; O2, CO2, C2H6, H2O, SiC

21. Example: Covalent Bond F2

22. Covalent Bonds

23. What is a Metallic Bond?

24. What is a Metallic Bond? Types of Elements in bond Electron Activity
“Sea of Electrons” surround the positive charges within the metal atom
Holds metal atoms together very strongly
Good conductors at all states, lustrous, very high melting points
Form Alloys – a mixture of metals
Examples of alloys: Brass (copper + zinc), Bronze (copper + tin)

25. Finds Gold And Drowns in a Sea of Electrons
What is a Metallic Bond?
Finds Gold And Drowns in a Sea of Electrons

26. A Sea of Electrons

27. Review What elements form an Ionic Bond?
What elements form a Covalent Bond?
What elements form a Metallic Bond?
What is the electron activity (what are the electrons doing) in each bond?