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Unit 3: Chemical BondingUnit 3: Chemical Bonding

OutlineOutline Ionic Bonding (Ch.7)

Valence electrons

Positive and negative ions and transition metal ions

Ionic bonding: Charge on compounds

Ionic compounds characteristics

Writing ionic compound formulas

Metallic Bonding

Metallic bond properties

Properties of metals explained by metallic bond

Metal alloys

Covalent Bonding (Ch.8)

Covalent bond

Lewis structure of a molecule

Naming molecules

Structural formulas

Lewis structures for polyatomic ions, Resonance structures

Molecular shapes

Bond polarity

Properties of Covalent compounds

Ionic Bonding (Ch.7)

Valence electrons

Positive and negative ions and transition metal ions

Ionic bonding: Charge on compounds

Ionic compounds characteristics

Writing ionic compound formulas

Metallic Bonding

Metallic bond properties

Properties of metals explained by metallic bond

Metal alloys

Covalent Bonding (Ch.8)

Covalent bond

Lewis structure of a molecule

Naming molecules

Structural formulas

Lewis structures for polyatomic ions, Resonance structures

Molecular shapes

Bond polarity

Properties of Covalent compounds

Ionic BondingIonic Bonding

Whenever two atoms or ions are held strongly together, we say that there is a chemical bondbetween them.

Chemical bond: A force that holds two atoms/ions together.

Whenever two atoms or ions are held strongly together, we say that there is a chemical bondbetween them.

Chemical bond: A force that holds two atoms/ions together.

Ionic BondingIonic Bonding

Chemical bonds can form by the attraction between a positive ion and a negative ion, or

they can form by the attraction between the positive nucleusand the negative electrons of another atom.

Chemical bonds can form by the attraction between a positive ion and a negative ion, or

they can form by the attraction between the positive nucleusand the negative electrons of another atom.

Ionic Bonding: Ion formationIonic Bonding: Ion formation

Positive Ion formation: loses valence electrons

Negative Ion formation: gains valence electrons (More information on unit 3 lecture slides)

Losing electrons: Always from the highest energy level.

Gaining electrons: Follows Aufbau principle.

Recall: Atoms gain or lose electrons to acquire the electron configuration of the nearest noble gas.

Positive Ion formation: loses valence electrons

Negative Ion formation: gains valence electrons (More information on unit 3 lecture slides)

Losing electrons: Always from the highest energy level.

Gaining electrons: Follows Aufbau principle.

Recall: Atoms gain or lose electrons to acquire the electron configuration of the nearest noble gas.

Ionic Bonding: Ionic compoundsIonic Bonding: Ionic compounds

When a cation and an anion form and them come close to each other, they are attracted to each other by their opposite charges.

An ionic bond is the electrostatic force that holds oppositely charged particles together in an ionic compound.

Ionic compounds are compounds that contain ionic bonds between two different types of ions.

When a cation and an anion form and them come close to each other, they are attracted to each other by their opposite charges.

An ionic bond is the electrostatic force that holds oppositely charged particles together in an ionic compound.

Ionic compounds are compounds that contain ionic bonds between two different types of ions.


Metals:

Metal atoms easily lose valence electrons.

Group 1, 2, 13 Naming: metal name + “ion”

Transition metals have an outer energy level of ns2 and the d sublevel that is filled is in a lower energy level (n-1)d

Transition metals commonly just lose the two s electrons from its valence shell and form the +2 ion.

Transition metals also can lose their d electrons and form a +3 ion too.

Naming: metal name + Roman numerals in brackets + “ion”

Metals:

Metal atoms easily lose valence electrons.

Group 1, 2, 13 Naming: metal name + “ion”

Transition metals have an outer energy level of ns2 and the d sublevel that is filled is in a lower energy level (n-1)d

Transition metals commonly just lose the two s electrons from its valence shell and form the +2 ion.

Transition metals also can lose their d electrons and form a +3 ion too.

Naming: metal name + Roman numerals in brackets + “ion”


Examples:

Write the electron configuration of the most likely ion and the charge of the ion.

1. Cs: [Xe]6s1 2. Ga: [Ar]4s23d104p1

3. Ag: [Kr]5s14d10 4. Sc: [Ar] 4s23d1

Examples:

Write the electron configuration of the most likely ion and the charge of the ion.

1. Cs: [Xe]6s1 2. Ga: [Ar]4s23d104p1

3. Ag: [Kr]5s14d10 4. Sc: [Ar] 4s23d1


Nonmetals:

Gain electrons

Groups 15 (-3 ion), 16 (-2 ion), 17 (-1 ion)

Name: non-metal element “–ide” + “ion”

Nonmetals:

Gain electrons

Groups 15 (-3 ion), 16 (-2 ion), 17 (-1 ion)

Name: non-metal element “–ide” + “ion”


Examples: Textbook p.209 Q5

Name the following ions.

1. Ag+ 2. Li+ 3. Br-

4. Ca2+ 5. S2- 6. B3+

7. As3- 8. H- 9. Cd2+

10. Se2-

Examples: Textbook p.209 Q5

Name the following ions.

1. Ag+ 2. Li+ 3. Br-

4. Ca2+ 5. S2- 6. B3+

7. As3- 8. H- 9. Cd2+

10. Se2-

Ionic Bonding: Ionic compoundproperties


Physical structure: (What it physically looks like)

In an ionic compound, large numbers of positive and negative ions exist together in a regular repeating pattern that balances the forces of attraction and repulsion between the ions.

Physical structure: (What it physically looks like)

In an ionic compound, large numbers of positive and negative ions exist together in a regular repeating pattern that balances the forces of attraction and repulsion between the ions.



Physical structure: eg. NaCl

Very organized arrangement

Each sodium ion is surrounded by six chloride ions and vice versa

Physical structure: eg. NaCl

Very organized arrangement

Each sodium ion is surrounded by six chloride ions and vice versa



Physical structure:

This 3D arrangement of particles in an ionic compound is called a crystal lattice.

In a crystal lattice, each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ions.

Physical structure:

This 3D arrangement of particles in an ionic compound is called a crystal lattice.

In a crystal lattice, each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ions.



Physical properties:

Melting point

Boiling point

Hardness

Electrical conductivity


Melting point

Boiling point

Hardness

Electrical conductivity




An ionic compound can’t conduct electricity as a solid, but when dissolved in water, it can conduct electricity.

Electrolytes are substances that can conduct electricity in aqueous solution.


An ionic compound can’t conduct electricity as a solid, but when dissolved in water, it can conduct electricity.

Electrolytes are substances that can conduct electricity in aqueous solution.




Lattice energy is the energy needed to separate 6.022 x 1023 ions from an ionic compound.

Larger ions: smaller lattice energy

Larger charges: larger lattice energy


Lattice energy is the energy needed to separate 6.022 x 1023 ions from an ionic compound.

Larger ions: smaller lattice energy

Larger charges: larger lattice energy


Many ionic compounds are binary.

This means that they contain only two different elements.

Binary ionic compounds: 1. Metal cation2. Nonmetal anion.

Many ionic compounds are binary.

This means that they contain only two different elements.

Binary ionic compounds: 1. Metal cation2. Nonmetal anion.


Compound formation:

Look carefully at the charges on both the metal cation and the nonmetal anion.

Ionic compounds have an overall charge of zero.

Compound formation:

Look carefully at the charges on both the metal cation and the nonmetal anion.

Ionic compounds have an overall charge of zero.


Compound formation:

Eg. Sodium and chlorine

Eg. Calcium and fluorine

Eg. Aluminium and oxygen

Textbook p. 212 Q7-11

Compound formation:

Eg. Sodium and chlorine

Eg. Calcium and fluorine

Eg. Aluminium and oxygen

Textbook p. 212 Q7-11


Another example:

Formation of ionic compound from Boron and Selenium

Another example:

Formation of ionic compound from Boron and Selenium

Ionic Bonding: Ionic compoundformulas


Writing Formulas:

Since an ionic compound is made up of ions arranged in a repeating pattern, the chemical formula for an ionic compound represents the simplest ratio of the ions involved.

Formula unit

Writing Formulas:

Since an ionic compound is made up of ions arranged in a repeating pattern, the chemical formula for an ionic compound represents the simplest ratio of the ions involved.

Formula unit



Writing Formulas:

Eg. Magnesium and Chlorine

1. Cation is always written first.

2. Subscripts represent the number of ions of each element in the compound.

Writing Formulas:

Eg. Magnesium and Chlorine

1. Cation is always written first.

2. Subscripts represent the number of ions of each element in the compound.



Writing Formulas: Monoatomic ions

A one-atom ion.

Common metal and nonmetal ions.

Eg. Groups 1,2,15,16,17


A one-atom ion.

Common metal and nonmetal ions.

Eg. Groups 1,2,15,16,17




Textbook p.221 Q19-23


Textbook p.221 Q19-23

Writing Formulas: Polyatomic ions

Ions that have more than one atom.

A polyatomic ion acts as an individual ion in a compound and its charge applies to the entire group of atoms.

Polyatomic ions exist as a unit, so do not change the subscripts within the ion.

Writing Formulas: Polyatomic ions

Ions that have more than one atom.

A polyatomic ion acts as an individual ion in a compound and its charge applies to the entire group of atoms.

Polyatomic ions exist as a unit, so do not change the subscripts within the ion.



Ion Name Ion Name

NH4+ Ammonium ClO- Hypochlorite

NO2- Nitrite ClO2

- Chlorite

NO3- Nitrate ClO3

- Chlorate

OH- Hydroxide ClO4- Perchlorate

CO32- Carbonate CrO4

2- Chromate

HCO3- Hydrogen carbonate Cr2O7

2- Dichromate

SO32- Sulfite S2O3

2- Thiosulfate

SO42- Sulfate O2

2- Peroxide

PO43- Phosphate MnO4

- Permanganate

HPO42- Hydrogen phosphate CN- Cyanide

H2PO4- Dihydrogen phosphate BrO3

- Bromate

CH3COO- Acetate IO3- Iodate

C2H3O2- IO4

- Periodate

Writing Names:

1. Write the name of the cation first.

For transition metals only: Write the “oxidation number” (=charge on the transition metal cation) in brackets next to the transition element’s name.

2. Write the name of the anion next to the name of the cation.

Writing Names:

1. Write the name of the cation first.

For transition metals only: Write the “oxidation number” (=charge on the transition metal cation) in brackets next to the transition element’s name.

2. Write the name of the anion next to the name of the cation.



Writing Names:

Eg. Iron, Fe, can be both the Fe2+ and the Fe3+ ion in different compounds.

So the ionic compound FeCO3 would be correctly named as “iron (II) carbonate”

And the ionic compound Fe2(CO3)3 would be correctly named as “iron (III) carbonate”.

Writing Names:

Eg. Iron, Fe, can be both the Fe2+ and the Fe3+ ion in different compounds.

So the ionic compound FeCO3 would be correctly named as “iron (II) carbonate”

And the ionic compound Fe2(CO3)3 would be correctly named as “iron (III) carbonate”.



unit 3: chemical bonding - ssi chemistryssichemistry.weebly.com/.../9/5/7/...bonding_notes.pdf ·...

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