Final M4 Chapter III (Chemical Bonding)

Chemical Bonding

Learning Objectives

Describe the formation of ions by electron loss/gain in order to obtain the electronic configuration of a noble gas.

What are ions?

Ions are formed when atoms gain or lose electrons.

Why do atoms form ions???

Question

3

Characteristics

• Belong to Group 18 of the periodic table.
• Stable and unreactive
• Exist as single atoms

4

5

Why are noble gases

unreactive?

6

What do you notice about the
valence shell?

2 2,8 2,8,8 2,8,8,8 2,8,8,8,8

Open Ended

What do you notice about the valence shell?

6

What do you notice about the
valence shell?

2 2,8 2,8,8 2,8,8,8 2,8,8,8,8

Ans: They have a full valence shell
🡪 noble gas configuration

7

How about other elements?

2,1

2,5

​2,2

​2,3

​2,4

​2,6

​2,7

7

How about other elements?

​Sadly, they do not have a full valence shell...

So how can other elements become like noble gases?

Multiple Choice

How can other elements become like noble gases?

• They gain or lose protons to form ions.

• They gain or lose electrons to form ions.

• They gain or lose neutrons to form ions.

• They gain or lose nucleons to form ions.

8

They form ions by gaining or losing electrons

​

They form ions by gaining or losing electrons

in order to achieve noble gas configuration.

Multiple Choice

Can noble gases form ions?

• Yes

• No

Multiple Choice

How do we know if an atom has a noble gas configuration?

• They have a charge.

• They gain or lose electrons to form an ion.

• They are neutral.

• They have a full valence electron shell

10

Ions

• An ion is an atom that has gained or lost an electron or electrons.

• An atom that loses an electron or electrons will have more protons than electrons, it will become an ion with a positive charge.

• An atom that gains an electron or electrons will have more electrons than protons, it will become an ion with a negative charge.

• Atoms that have a charge can only gain or lose electrons they cannot gain or lose protons.

Multiple Choice

An ion is an atom that has gained or lost _______.

• protons

• neutrons

• electrons

Multiple Choice

An atom that gains electrons will have a ___ charge.

• negative

• positive

Multiple Choice

An atom that loses electrons has a ____ charge.

• negative

• positive

Cations and Anions

• Cations- pronounced cat-ion- is an ion with a positive (+) charge (it will be an ion that lost electrons). It has more protons than electrons.

• Anions- pronounced an-ion- is an ion with a negative (-) charge (it will be an ion that gained electrons). It has more electrons than protons.

Multiple Choice

Cations have a positive charge, which means they have _____ electrons.

• gained

• lost

Multiple Choice

An ion that has negative charge has gained electrons, it is called a________.

• anion

• cation

Valence Electrons and Ions

• Atoms gain or lose electrons from the highest energy level.

• The atoms in the highest energy level are called valence electrons.

• Elements in group 1 like Lithium [Li] have 1 valence electron.

• Elements in group 2 like Berylium [Be] have 2 valence electrons.

• Elements in group 13 like Boron [B] have 3 valence electrons.

• Elements in group 14 like Carbon [C] have 4 valence electrons.

• Elements in group 15 like Nitrogen [N] have 5 valence electrons.

• Elements in group 16 like Oxygen [O] have 6 valence electrons.

• Elements in group 17 like Flourine [F] have 7 valence electrons.

Multiple Choice

Valence electrons are atoms of the outer most energy level, there is a maximum number of eight.

• True

• False

Multiple Choice

How many valence electrons does an atom of silicon have?

• 3

• 4

• 5

• 6

Multiple Choice

Be, Mg, and Ca have ___ valence electrons.

• 1

• 2

• 3

• 4

Octet Rule

• The octet rule determines if an atom will gain or lose electrons.

• The outer level of an atom has eight electrons.

• An atom will gain or lose electrons to have a full outer energy level.

• Atoms of metals tend to lose their valence electrons.

• Nonmetals tend to gain or share electrons to achieve a full octet.

Multiple Choice

Atoms will gain or lose electrons in order to have a full outer energy level this is called the _____ rule.

• valence

• cation

• octet

• anion

Will an atom gain or lose an electron?

• Atoms in group 1, 2, and 13 lose electrons. Remember the atom want a full outer energy level.

• For atoms that lose electrons, they empty the outer most energy level.

• For groups 1, 2 and 13 - atoms lose electrons forming a positive ion.

• For groups 15, 16 and 17 - atoms gain electrons forming a negative ion.

• For group 14- atoms can gain or lose electrons forming a positive or negative ion.

Multiple Choice

Group 2 will _____ electrons, forming an ion with a positive charge.

• gain

• lose

Multiple Choice

Group 17 elements _____ electrons, forming a negative charge.

• gain

• lose

Elements that lose electrons form CATION

• Atoms that lose electrons have more protons than electrons, the ion that forms has a positive charge and is a cation.

• They are part of representative groups 1 , 2 , 13 and 14 in the periodic table.

• For example sodium [Na] atom is in group 1, it will lose 1 electron and will have the +1 charge to make it a sodium ion [Na⁺].

• For example magnesium [Mg] atom is in group 2, it will lose 2 electron and will have the +2 charge to make it a magnesium ion [Mg⁺²].

  CONTINUE COPYING THE EXAMPLES IN THE WHITEBOARD

Multiple Choice

What is the charge on an ion of sodium (Na)?

• +1

• +2

• +3

• +4

Multiple Choice

Aluminum forms an ion with +3 charge, what group is it in?

• 1

• 2

• 13

• 14

Elements that gain electrons form ANION

• Nonmetals tend to gain or share electrons forming negative ions or anions.

• When an atom gains an electron or electrons it forms an ion with more electrons than protons. It forms a negative ion (an anion).

• To determine the charge of a negative ion (anion) subtract 8 (to obey with the octet rule)

• Example- Flourine atom is in group 17. Group 17 has 7 valence electrons subtract 8 (to obey with the octet rule) so that would be (7-8= -1) . That makes a Flourine ion [F^-].

CONTINUE COPYING THE EXAMPLES IN THE WHITEBOARD

Multiple Choice

An atom of Br will form an anion. What will the charge of the anion be?

• +1

• +2

• -1

• -2

Multiple Choice

Phosphorous forms an anion with a charge of -3 what representative group is it part of?

• 13

• 14

• 15

• 16

​Ionic, covalent and metallic bonds

Multiple Choice

Where are metals located on the periodic table?

• Blue

• Green

• Red

Multiple Choice

Where are the nonmetals located on the periodic table?

• Blue

• Red

• Green

Multiple Choice

A bond between a metal and a nonmetal is called a __________.

• covalent bond

• ionic bond

• metallic bond

• transfer bond

Multiple Choice

What makes up a covalent bond?

• Metal and a Metal
• Metal and a nonmetal
• nonmetal and a nonmetal
• metal and a metallid

Multiple Choice

NO₂

• Ionic Bond

• Covalent Bond

• Both bonds

• Neither bond

Multiple Choice

MgBr₂

• Ionic Bond

• Covalent Bond

• Both bonds

• Neither bond

Multiple Choice

Predict the bond that will form between Be and F.

• Ionic

• Covalent

Multiple Choice

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

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

Identify the following compound as ionic or covalent: Na₂SO₄

• ionic

• covalent

Multiple Choice

A bond between a nonmetal and a nonmetal is called a

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

A bond between a metal and a nonmetal is called

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

Identify the following compound as ionic or covalent: CF₄

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

Identify the following compound as ionic or covalent: MgO

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

Identify the following compound as ionic or covalent: SO₂

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

Identify the following compound as ionic or covalent: Na₂SO₄

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

H2O, Ionic or Covalent?

• ionic bond

• covalent bond

• metallic bond

Multiple Choice

NaBr, Ionic or Covalent?

• ionic bond

• covalent bond

• metallic bond