12/16 Review Chemical Bonding

Draw

Draw the Bohr diagram of the element Nitrogen?

How many electrons will you draw ?

Valence Electrons

• Recall: valence electrons are the electrons in the outermost energy level

• MOST IMPORTANT FOR BONDING

• Hydrogen and Helium only need 2 valence electrons in order to be stable

• The rest of the elements need 8

Why do elements bond?

• Full outer energy levels mean they are stable

• If the atoms of elements do not have full energy levels, they will seek out other atoms with whom they can join

• Elements will gain, lose, or share electrons to fill up the outer energy level (8 is the magic number) and become chemically stable.

Multiple Choice

This is a Bohr Diagram of Aluminum. How many valence electrons does Aluminum have?

• 3

• 5

• 6

• 11

Multiple Choice

Why do elements bond together?

• Because it is easier to survive in the world if they are bonded

• They share or transfer electrons to get a full outer shell to attain octet rule

• They like to have a partner element to make them stronger

Noble Gases (Group 18)

• The Noble Gases already have full outer energy levels

• They are chemically stable and very rarely form compounds

Other Elements

• Other elements do not have 8 valence electrons

• They will form chemical bonds in order to become chemically stable.

Multiple Choice

Which elements on the periodic table do NOT bond?

• Group 1 Alkali metals

• All metals

• All nonmetals

• Noble Gases

Oxidation Numbers

• Oxidation numbers tell how many electrons an atom gains, loses, or shares to become stable

• Valence electrons determine the number in oxidation numbers

• During ionic bonding, metals will lose those valence electrons because they will be transferred to the nonmetals

• So metals lose those electrons and nonmetals gain them.

Oxidation Numbers

• In covalent bonding, one nonmetal will be assigned a positive number and the other one(s) will be assigned a negative number

• Examples of Oxidation Numbers:

  Lithium:

  Chloride:

  
  

Chemical Bond

• A chemical bond is the force of attraction between two different atoms

• Sometimes it can occur between two of the same atoms

What are the types of Chemical bond?

Types of Bonds

There are three types of chemical bonds:

• Ionic

• Covalent

• Metallic

Ionic Bonds

• A transfer of electrons from metals to nonmetals

• The smallest unit of the compound is the ion

• The bond occurs because of the attraction between the positive ion and the negative ion

• Metal and Non-metal

Open Ended

Give an example of Chemical formula that is Ionic Bond

Multiple Choice

What elements generally make an ionic bond?

• 
  metal and nonmetal

  
  

• 2 or more nonmetals

• metal

• none of the above

Covalent Bonds

• Sharing of electrons between nonmetals and metalloids

• The bond occurs because the atoms must stay close together to share electrons

Open Ended

Give an example of Chemical formula that is Covalent bond

Multiple Choice

What elements generally make a covalent bond?

• metal and nonmetal

• 
  2 or more nonmetals

• 
  metal

• 
  none of the above