Topic 2 (Types of Bonding)

Question 1

Define the term ion.

Answer 1

A charged particle by gaining or losing electrons.

Question 2

What is meant by the term ionic bonds?

Answer 2

The transfer of electrons from a metal atom to another non-metal atom forming positive and negative ions.

Question 3

What kind of force attracts ionic bonds?

Answer 3

Strong electrostatic forces between the positive and negative ions.

Question 4

Describe the properties of ionic compounds.

Answer 4

*High melting and boiling points.
*Soluble in water.
*Usually solids.
*They conduct electricity when molten or aqueous.

Question 5

Why do ionic compounds have high melting and boiling points?

Answer 5

This is because the strong electrostatic forces between the ionic bonds require huge amounts of energy to be broken down.

Question 6

Why do ionic bonds conduct electricity when molten or aqueous?

Answer 6

This is because the ions are free to carry the charge.

Question 7

Define the term “Giant Ionic Structure”.

Answer 7

Regular arrangement of alternating oppositely charged positive and negative ions.

Question 8

State the valency of each compound ion.

Answer 8

Ammonium (NH4): 1+
Hydroxide (OH): 1-
Nitrate (NO3): 1-
Nitrite (N02): 1-
Hydrogen Carbonate (HCO3): 1-
Carbonate (CO3): 2-
Sulfate (SO4): 2-
Sulfite (SO3): 2-
Phosphate (PO4): 3-
Phosphite (PO3): 3-

Question 9

Define the term Covalent Bonds.

Answer 9

The sharing of electrons between non-metals.
Covalent bonding is for non-metals only since only non-metals need to gain electrons.

Question 10

Describe the term Molecules.

Answer 10

A group of atoms held together by covalent bonds.

Question 11

Describe the properties of covalent compounds.

Answer 11

*Low melting and boiling points.
*Do not conduct electricity.
*Mainly gases and liquids but a few are solids.
*Less soluble in water than ionic compounds.

Question 12

Why do covalent compounds have low melting and boiling points?

Answer 12

This is because the weak intermolecular forces between the molecules need low amounts of energy to be broken down.

Question 13

Why do covalent compounds not conduct electricity?

Answer 13

This is because there are no free/mobile electrons to carry the electric charge.

Question 14

Define the term Macromolecules.

Answer 14

Macromolecules are made of billions of atoms bonded together in a covalent structure.

Question 15

What is meant by the term allotropes?

Answer 15

When the same element exists in several physical forms and structures, it is said to be exhibit allotropy.

Question 16

Mention two allotropes of carbon.

Answer 16

Diamond and Graphite.

Question 17

Describe the structure of Graphite.

Answer 17

In graphite, each carbon atom is linked with 3 other carbon atoms by single covalent bonds resulting in the hexagonal ring which is arranged in a layer. The layers of hexagons are bonded by weak forces, so the layers slide over each other.

Question 18

Describe the properties of Graphite.

Answer 18

*Soft and slippery because the layers of hexagons can slide over each other.
*A good conductor of electricity.

Question 19

Why does graphite conduct electricity?

Answer 19

This is because each carbon atom has four outer electrons and graphite only bonds to 3, so the fourth electron is free to move and carry the charge.

Question 20

What are the uses of graphite?

Answer 20

*Electrodes - it can conduct electricity and is unreactive.
*Pencils - it’s slippery and can slide through paper.
*Lubricant - it’s soft.

Question 21

Describe the structure of Diamond.

Answer 21

Each carbon atom is bonded to four other carbon atoms by strong covalent bonds in a tetrahedral arrangement.

Question 22

Describe the properties of diamond.

Answer 22

*Very hard because each atom is held by four strong bonds.
*Very high melting point because it needs very big amounts of energy to break the strong bonds.
*Does not conduct electricity because there are no free electrons to carry the charge.

Question 23

What are the uses of diamond?

Answer 23

*Jewelry - it’s shiny.
*Cutting and drilling - it’s very hard, strong and sharp.

Question 24

Describe the structure of Silicon dioxide.

Answer 24

Each silicon atom is bonded to 4 oxygen atoms, and each oxygen atom is bonded to 2 silicon atoms.

Question 25

Describe the physical properties of silicon dioxide.

Answer 25

*Very high melting point - it has very strong covalent bonds that need high amounts of energy to be broken down.
*Very hard - due to the strong bonds.
*Does not conduct electricity - there are no free electrons to move.
*Insoluble in water and organic solvents.

Question 26

What is meant by the term metallic bond?

Answer 26

The force of attraction between the layers of positive metal ions and the sea of delocalized negative electrons.

Question 27

Describe the arrangement in a metallic lattice.

Answer 27

Regularly arranged layers of positive ions embedded in a sea of delocalized negative electrons.

Question 28

Describe the properties of metals.

Answer 28

*Malleable - they can bent and pressed into shapes.
*Ductile - they can be drawn into wires.
*Good conductors of heat
*Good conductors of electricity - there are free electrons which can move through the lattice carrying the charge.
*High melting and boiling points - due to the strong forces between the positive ions and negative electrons.

Question 29

Why are metals malleable and ductile?

Answer 29

This is because the layers of positive ions can slide over each other without the metallic bond breaking.