Bonding- Covalent, Metallic, and Ionic

Bonding- Covalent, Metallic, and Ionic

OBJECTIVES

• Identify types of chemical bonds based on the elements in them

• Explain chemical bonding in terms of the behavior of electrons

CHEMICAL FORMULAS

• Tells you how many of each element a compound contains

• Subscripts tell you how many of each atom is present

THE NUMBER OF ATOMS IN A COMPOUND

• Review the number of atoms in a compound

• For example H2O

• 2 H & 1 O

Multiple Choice

Which of the following accurately describes the chemical formula of the molecule shown above?

• 3CH₈O

• C₃H₇O

• C₄H₈O₂

• C₃H₈O

Multiple Choice

Which of the following statements accurately describes the number of atoms in a molecule of ammonia (NH₃)?

• Three atoms of nitrogen and three atoms of hydrogen

• One atom of nitrogen and three atoms of hydrogen

• Three atoms of nitrogen and one atom of hydrogen

• One atom of nitrogen and one atom of hydrogen

Multiple Choice

How many atoms of carbon are in a molecule of vinyl chloride (C₂H₃Cl)?

• 1

• 3

• 6

• 2

Multiple Choice

How many elements are in C₆H₁₂O₆?

• 1
• 2
• 3
• 4

Multiple Choice

How many atoms are there TOTAL in:
H₂SO₄

• 6
• 5
• 7
• 3

Multiple Choice

Which is the correct formula for:
 three hydrogen (H)
one sulfur (S)
four oxygen (O)

• H₃SO₄
• HSO₄
• H₄S₃O
• H₂O

Multiple Choice

How many atoms of carbon (C) are in C₆H₁₂O₆?

• 3
• 6
• 12
• 24

CHEMICAL BONDS

• A chemical bond is an attraction between 2 atoms or ions.

• Bonding occurs because it lowers the energy of the system.

• Three broad classifications: Ionic Covalent Metallic

GENERAL RULE

• IONIC : Metal + Non metal or 

  
  

  IONIC : Metal + polyatomic ion 

• COVALENT : Nonmetal + Nonmetal

• Metallic : Metals only

CHEMICAL BONDS

• This happens when atoms

• lose electrons

• gain electrons

• share electrons

What makes this happen?

• How many electrons will a stable atom have in its valence shell?

• If an atom does not have a full valence shell it will BOND to achieve stability

• Chemical Bonds are the forces that hold atoms together in a compound

OCTET RULE

Atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons. 

Atoms react with each other in chemical reactions in a quest to have complete outer electron energy levels like the noble gases.

What makes this happen?

• Electronegativity is the key

• more specifically, the DIFFERENCE in electronegativity

• END : subtract the 2 electronegativities of the atoms

What makes this happen?

• The greater an atom's electronegativity, the greater its ability to attract electrons

• In a comound, the element wtih the greater electronegativity will be the more negative species

• The element with the lower electronegativity is referred to as the more 'electropositive' element.

ELECTRONEGATIVITY

• END Range is the difference in electronegativity values between atoms

• Determines the type of bond

• Ionic bonds have different electronegativities

• Covalent bonds have similar electronegativities

Electrons are the Key

• If valence electrons are transferred from one atom to another, it is called IONIC Bonding

• If valence electrons are shared by atoms, it is called COVALENT bonding

• If valence electrons move freely between atoms, it is called METALLIC bonding

WHY BOND AT ALL?

• A chemical bond is a link between atoms resulting from the mutual attraction of nuclei for electrons.

• metals are losers 

• non-metals are gainers 

• For two atoms to “bond”, they must collide in the correct orientation, and there must be a decrease in potential energy.

METALLIC BONDING

The valence electrons in metals become detached from the individual atoms so that metals consist of a close packed lattice of positive ions in a sea of delocalized electrons.

Also called, Mobie Sea of electrons

METALLIC BONDING

• Metal ions near each other share valence electrons

• These valence electrons flow freely between all of the ions

• These delocalized electrons are why metals conduct heat and electricity

• It is also why metals are malleable and ductile

IONIC BONDING

• Metals + Nonmetals

• Make IONIC bonds

• Transfer electrons

• High electronegativity difference

IONIC BONDING

• Form Crystalline Lattice (crystals)

• Have high melting and boiling points

• Hard

• Brittle

• Conduct electricity when dissolved in water

COVALENT BONDING

• Nonmetal + Nonmetal

• Make COVALENT bonds

• Share electrons

• Low electronegativity difference

COVALENT BONDING

• Have Lower melting and boiling points

• Tend to be flammable

• When dissolved in water they do not conduct electricity

• Soft or brittle solid

• Can also form crystals

Let’s Practice!

Using what you learned in the Ionic & Covalent Bonding

Examine the compounds and identify where the elements are located in the PT 

Reminder:

IONIC - Metal + Nonmetal

COVALENT - nonmetal + Nonmetal

Multiple Choice

Identify the following compound as ionic or covalent: Ca(OH)₂

• ionic

• covalent

Multiple Choice

Identify the following compound as ionic or covalent: CO

• ionic

• covalent

Multiple Choice

Identify the following compound as ionic or covalent: Na₂SO₄

• ionic

• covalent

Multiple Choice

What type of bond involves the sharing of electrons between atoms?

• covalent bond

• ionic bond

• metallic bond

• transfer bond

Multiple Choice

Identify the following compound as ionic or covalent: CF₄

• ionic

• covalent

Multiple Choice

A bond between a nonmetal and a nonmetal is called a(n)

• covalent bond

• ionic bond

• metallic bond

• transfer bond

Multiple Choice

Identify the following compound as ionic or covalent: MgO

• ionic

• covalent

Multiple Choice

A bond between a metal and a nonmetal is called a(n)

• covalent bond

• ionic bond

• metallic bond

• transfer bond

Multiple Choice

Identify the following compound as ionic or covalent: SO₂

• ionic

• covalent

Multiple Choice

Nitrogen and Oxygen will make a ____________ bond

• ionic

• covalent

• metallic

Multiple Choice

Carbon and Oxygen will make a ___________ bond.

• ionic

• covalent

• metallic

Multiple Choice

Sodium and Bromine will make a _____ bond.

• ionic

• covalent

• metallic

Multiple Choice

Beryllium and sulfur will form a ______ bond

• ionic

• covalent

• metalloid

Multiple Choice

The chemical bond between a non-metal and another non-metal will be a ________ bond.

• metal

• ionic

• covalent

• polar

Multiple Select

Which of these are considered properties of metals? (choose ALL that apply)

• brittleness

• low melting point

• luster (shininess)

• malleability

• ductility

Multiple Choice

Why do metals conduct

• They are shiny
• The electrons are held tightly within the lattice
• The electrons are delocalised and able to move
• The electrons are shared between two metal ions

Multiple Choice

What is the basis of a metallic bond?

• the attraction of neutral metal atoms.
• the attraction between protons and neutrons.
• the attraction between positive metal ions and interlocking electrons.
• the attraction between positive metal ions and free floating electrons.