BONDINGBONDING

PREVIEWPREVIEW

Bonds Between Atoms

Covalent

Ionic

Polyatomic Ions

Metallic

Molecular Substance Polar

NonpolarCoordinate Covalent

Network Solids

What are we going to learn about???

The following words will be used most lessons…

• Anion- negative ion• Cation-positive ion• Octet Rule- rule that states that atoms tend to gain, lose,

or share electrons so that each atom has full outermost energy level which is typically 8 electrons.

• Polyatomic Ion- charged group of covalently bound atoms

• Monatomic Ion- ion formed from a single atom• Molecule-neutral group of atoms united by covalent

bonds

• Valence electrons- an atoms outer most electrons.

• Unshared Pair- pair of electrons that is not involved in bonding but instead is held exclusively by one atom.

Marriage

Divorce

Forming of a bond is like marriage

•More stable

•exothermic

The breaking of a bond relates to a divorce.

•Less stable

•Endothermic

Ionic Bonds•What is an Ionic Bond?

- An Ionic Bond is a chemical bond resulting from the TRANSFER of electrons from one bonding atom to another

• When is an ionic bond formed?

- An ionic bond is formed when a cation (positive ion) transfers electrons to an anion (negative ion).

What are some characteristics of an ionic bond?

1. Crystalline at room temperatures

2. Have higher melting points and boiling points compared to covalent compounds

3. Conduct electrical current in molten or solution state but not in the solid state

4. Soluble in H2O5. Strong electrostatic

attractive forces between ions

Covalent Bonds•What is a Covalent Bond?

- A covalent bond is a chemical bond resulting from SHARING of electrons between 2 bonding atoms.

• What forms a covalent bond?

- A covalent bond is formed between two nonmetals.

What are some characteristics of a covalent bond?

1. Covalent bonds have definite and predicable shapes.

2. Low melting solides, Liquids or Gases at normal temperatures.

3. Bonds stretch, bend, rotate

4. Low melting and boiling points

5. Not usually soluble in water

6. Not electrically conductive

Lewis Dot Structures

• Lewis dot structures are a shorthand to represent the valence electrons of an atom.

• The structures are written as the element symbol surrounded by dots that represent the valence electrons.

• The Lewis structures for the elements in the first two periods of the periodic table are shown below.

1 2 13 14 15 16 17 18H He:

Li Be B C N O : F :Ne :

Covalent Bonds can have multiple bonds, so you should be familiar with the following…

Single Covalent Bond- chemical bond resulting from sharing of an electron pair between two atoms.

Double Covalent Bond- chemical bond resulting from sharing of two electron pairs between two atoms.

Triple Covalent Bond-chemical bond resulting from sharing of three electron pairs between two atoms.

There are five different categories associated with covalent bonds. What are the 5 different categories?

Covalent

Molecular Substance Polar

NonpolarCoordinate Covalent

Network Solids

c

First, we are going to look at Polar Covalent…

What is polar covalent?

-Polar covalent is a description of a bond that has an uneven distribution of charge due to an unequal sharing of bonding electrons.

The boy is not equally sharing with anyone else but rather taking all the food for himself.

Next, we are going to look at Non-Polar Covalent…

What is non-polar covalent?-Non polar covalent is a covalent bond that has an even distribution of charge due to an equal sharing of bonding electrons.

This couple is non- polar because they are sharing the drink equally between them.

Next, we are going to look at Coordinate Covalent…

What is a Coordinate Covalent Bond?-A coordinate covalent bond is a bond formed when one atom donates both electrons that are shared.

People donate their blood to help others just like atoms “donate” electrons to form stable octets.

Now, we are going to look at Network Solids…

What is a Network Solid?-A network solid is a solid that has covalently bonded atoms linked in one big network or one big macromolecule.

Characteristics of a Network Solid.

1. Poor conductors of heat and electricity

2. Hard / Strong

3. High melting and boiling points (3D- covalent networks)

Common examples of network solids include diamond and graphite.

Next, we are going to look at Molecular Substances…

What is a molecular substance?

-A molecular substance is a substance that has atoms held together by covalent bonds.

-The molecules are held together by intermolecular forces (forces among molecules)

-I2, H2O, Polymers (high & low density)

Metallic BondingWhat is a Metallic Bond?

- A metallic bond occurs in metals. A metal consists of positive ions surrounded by a “sea” of mobile electrons.

Name 4 Characteristics of a Metallic Bond.

1. Good conductors of heat and electricity

2. Great strength

3. Malleable and Ductile

4. Luster

This shows what a metallic bond might look like.

Polyatomic Bonds

What is a Polyatomic Bond?

- A polyatomic bond is charged group of covalently bonded atoms. It is made up of more than one atom.

Polyatomic ions usually have a charge because the collection of atoms has either gained an extra electron or else it has lost an electron.

Trigonal Planer

Tetrahedral

Linear

Octahedral

Trigonal Bipyramidal

Notice all the different types of shapes that the atoms Notice all the different types of shapes that the atoms can take on because of their bonding…can take on because of their bonding…

Just as a summary to what each bond looks like…