Introduction to General Chemical Bonding

Objective 1: WHAT IS A
CHEMICAL BOND?

► A chemical bond is an attraction that

holds atoms together.

► Why do elements bond? In nature, the

lowest energy arrangement is favored.
When chemical bonds form, energy is
released, resulting in a lower energy
arrangement.

Multiple Choice

A ____________is the force that holds atoms together in a compound.

• Chemical Formula

• Chemical Reaction

• Chemical Bond

• Synthesis Reaction

Multiple Choice

What are the outermost electrons that participate in chemical bonding called?

• Bonding electrons

• Valence electrons

• Outer electrons

• Chemical electrons

Objective 2:
ELECTRONEGATIVITY AND ITS
TREND (REVIEW)

► Electronegativity is the tendency of an

atom in a molecule to attract shared
electrons to itself.

► Electronegativity generally increases

going from left to right across a period
and decreases going down a group.

Multiple Choice

Measure of the tendency of an atom to attract a bonding pair of electrons is known as...

• electronegativity

• bond polarity

• angular momentum

• valence electrons

Electronegativity Trend

►

Increases across the period and decreases down the group.

Multiple Choice

What does electronegativity do as you go across a period?

• decrease

• no pattern

• stay the same

• increase

Multiple Choice

Which of the following is the most electronegative element?

• nitrogen

• phosphorus

• arsenic

• lithium

Multiple Choice

What elements have zero electronegativity?

• metals

• nonmetals

• metalloids

• noble gases

Objective 3: TYPES OF
BONDS

► Ionic bonding- results from the electrical

attractions between positive ions
(cations) from metals and negative ions
(anions) from nonmetals. Ionic bonding
forms a neutral arrangement of atoms
called an ionic compound.

Types of Bonds – Ionic
Bonding

► Ionic compound- composed of positive cations

and negative anions that are combined so that
the net charge is zero.

► Formula unit- simplest collection of atoms from

which an ionic compound’s formula can be
established. Example: the formula unit for sodium
chloride is NaCl; a ratio of one Na+ ion to one Cl-
ion.

Multiple Choice

A charged particle that has gained or lost electrons is called a _____.

• molecule

• ion

• isotope

• element

Multiple Select

The sum of the charges on the ions in a unit of the compound is ___________. 

• positive

• negative

• zero

• ±1

Draw

Draw the Lewis Dot Structure for an Oxygen atom and an Oxygen ion.

► Covalent bonding- results from the sharing of electron

pairs between two atoms. These two atoms are usually
both nonmetals. Covalent bonding forms a neutral
arrangement of called a molecule.

Covalent Bonding - True Molecules

Types of Bonds

Diatomic
Molecule

Multiple Choice

What two types of atoms make a covalent bond?

• 2 Nonmetals

• 1 Nonmetal and 1 Metal

• 2 Metals

• 2 Noble Gases

Multiple Choice

How are covalent bonds explained?

• When one atom takes the other atom's electron

• When the atom shares an electron with an another atom

• When the two nucleus merge

• When the neutrons leave the nucleus

Metallic Bonding - “Electron Sea”

RETURN

Types of Bonds

► Metallic bonding - Metallic bonds are found only in

metals. Freely moving valence electrons are attracted
to the positive 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.

Multiple Choice

What is meant by the term "sea of electrons"?

• It's what we call all the free floating electrons in a metal.

• It's what we call electrons that are floating in a liquid.

• It's the total number of electrons in a metal atom.

• It's the total number of electrons in the ocean.

Multiple Choice

Electrons that are free to move in metals

• delocalized electrons

• oxidation number

• chemical bond

• salts

Objective 4: RELATE
ELECTRONEGATIVITY DIFFERENCES
TO BOND POLARITY.

► The greater the EN difference in a

compound, the more polar the bond.

► Bonding electrons will be unequally

shared if there is an electronegativity
difference. The atom with the higher
electronegativity value will have a
stronger attraction for the shared
electrons. If the EN difference is greater
than or equal to 1.7, the bond is
considered an ionic bond.

Bond Polarity

Examples:

►

Cl2

►

HCl

►

NaCl

3.0-3.0=0.0
Nonpolar

3.0-2.1=0.9
Polar

3.0-0.9=2.1
Ionic

Bond Polarity

► Most bonds are a

blend of ionic and
covalent
characteristics.

► Difference in

electronegativity
determines bond
type.

Multiple Choice

What elements have zero electronegativity?

• metals

• nonmetals

• metalloids

• noble gases

Objective 5: IONIC BONDING

►

Electronegativity difference is greater than or equal to
1.7

►Involves the transfer of electrons to make a full octet

►Example: NaCl

►NaCl: ____ - _____ = ________

Multiple Choice

The difference in electronegativity affects the type of bond will be formed. What type of bond would be formed with a difference of 0.6?

• Covalent

• Polar Covalent

• Ionic

Multiple Choice

The difference in electronegativity affects the type of bond will be formed. What type of bond would be formed with a difference of 2.0?

• Covalent

• Polar Covalent

• Ionic

Multiple Choice

The difference in electronegativity affects the type of bond will be formed. What type of bond would be formed with a difference of 0.3?

• Covalent

• Polar Covalent

• Ionic

Types of Bonds

Ionic

Covalent

Metallic

Bond Formation

e- are

transferred
from metal
to nonmetal

e- are shared
between two

nonmetals

e- are

delocalized
among metal

atoms

Type of
Structure

Crystal
Lattice

True

Molecules

“Electron

Sea”

Physical State

Solid

Liquid or Gas

Solid

Melting Point

High

Low

Very High

Soluble in Water

Yes

Usually Not

No

Electrical
Conductivity

Yes (solution

or liquid)

No

Yes (any

form)

Other Properties

Odorous

Malleable,

Ductile,
Lustrous

Multiple Select

Which of the following is true about Ionic Bonds? (select ALL TRUE options)

• High melting point

• Low melting point

• Can dissolve in water

• Cannot dissolve in water

• Can conduct electricity

Multiple Select

Which of the following is true about Covalent bonds? (select ALL true options)

• High melting point

• Low melting point

• Cannot conduct electricity

• Can conduct electricity

Multiple Choice

Excellent conductors as solid and liquid due to a sea of delocalised electrons.

• covalent

• metallic

• ionic