Chemical bonding and structure

Question 1

Define ionic bonds

Answer 1

Ionic bonds are strong electrostatic forces of attraction between oppositely-charged ions

Question 2

Define electronegativity

Answer 2

Electronegativity is the ability of an atom to attract a shared pair of electrons towards itself

Question 2

What is the structure of ionic compounds

Answer 2

• Closely packed and arranged in an orderly manner
• Held in fixed positions by strong electrostatic forces of attraction

Question 3

Define allotropes

Answer 3

Allotropes are different forms of the same element

Question 3

Define metallic bonds

Answer 3

Metallic bonds are the strong electrostatic forces of attraction between the positive metal ions and the ‘sea’ of free-moving valence electrons

Question 4

Give examples of giant molecular structure

Answer 4

• Diamond
• Silicon
• Silicon dioxide

Question 5

Give examples for giant molecular layered structure

Answer 5

• Graphite

Question 6

What particles are in a giant ionic structure

Answer 6

Oppositely-charged ions

Question 7

What particles are in a simple molecular structure

Answer 7

Simple molecules

Question 8

What particles are in a giant molecular structure

Answer 8

Non-metal atoms

Question 9

What particles are in a giant molecular layered structure

Answer 9

Carbon atoms

Question 10

What particles are in a giant metallic structure

Answer 10

Positive metal ions in a ‘sea’ of free-moving valence electrons

Question 11

How are particles bonded in giant molecular structure

Answer 11

Each atom is covalently bonded to 4 other atoms in tetrahedral arrangement

Question 12

How are particles bonded in giant molecular layered structure

Answer 12

Each carbon atom is covalently bonded to 3 other carbon atoms in hexagonal arrangement

Question 13

Describe melting/boiling points of simple molecular structure

Answer 13

• Simple molecular substances have low melting and boiling points
• Small amount of energy needed to overcome weak intermolecular forces of attraction between molecules

Question 13

Describe melting/boiling points of giant ionic structure

Answer 13

• Ionic compounds have high melting and boiling points
• Large amount of energy is needed to overcome strong electrostatic forces of attraction between oppositely-charged ions

Question 14

Describe melting/boiling points of giant molecular structure

Answer 14

• Giant molecular substances have high melting and boiling points
• Large amount of energy is needed to break the strong covalent bonds between atoms

Question 15

Describe melting/boiling points of giant metallic structure

Answer 15

• Metals have high melting and boiling points
• Large amount of energy needed to overcome strong electrostatic forces of attraction between positive metal ions and the ‘sea’ of free-moving valence electrons

Question 16

Describe electrical conductivity of giant ionic structure

Answer 16

• Giant ionic compounds are electrical insulators when solid
• Oppositely-charged ions are held in fixed positions by strong electrostatic forces of attraction
• No free-moving ions available to conduct electricity
• Giant ionic compounds are good electrical conductors when molten/aqueous
• Strong electrostatic forces of attraction between oppositely-charged ions have been overcome
• Free-moving ions are available to conduct electricity

Question 17

Describe melting/boiling points of giant molecular layered structure

Answer 17

• Giant molecular layered substances have high melting and boiling points
• Large amount of energy needed to break strong covalent bonds between atoms in each layer

Question 18

Describe electrical conductivity of simple molecular structure

Answer 18

• Simple molecular substances are electrical insulators
• No free-moving ions or valence electrons available to conduct electricity

Question 19

Describe electrical conductivity of giant molecular structure

Answer 19

• Giant molecular substances are electrical insulators
• Each atom uses all of its valence electrons for covalent bonding
• No free-moving electrons available to conduct electricity

Question 20

Describe electrical conductivity of giant molecular layered structure

Answer 20

• Giant molecular layered substances are good electrical conductors
• Each carbon atom only uses 3 out of 4 of its carbon atoms for covalent bonding
• Valence electrons not used in bonding are free-moving and can conduct electricity

Question 21

Describe electrical conductivity of giant metallic structure

Answer 21

• Metals are good electrical conductors
• There is a ‘sea’ of free-moving valence electrons available to conduct electricity

Question 22

What substances are soluble

Answer 22

• Giant ionic soluble in water
• Simple molecular soluble in organic solvents

Question 23

What other special properties do giant molecular layered structures have

Answer 23

Soft and slippery
- Layers of carbon atoms are held by weak intermolecular forces of attraction
- Layers are able to slide over one another easily when force applied

Question 23

What other special properties do giant molecular structures have

Answer 23

Hard
- All carbon atoms are held by strong covalent bonds

Question 24

What other special properties do metals have

Answer 24

Ductile and malleable
- Arranged in orderly layers
- Layers of metal ions can slide over one another easily when force applied