Bonding

Question 1

What do ionic compounds contain?

Answer 1

A metal and a non-metal.

Question 2

Charged particles formed from ionic bonding?

Answer 2

Ions.

Question 3

What is a positive ion called?

Answer 3

A cation.

Question 4

What is a negative ion called?

Answer 4

An anion.

Question 5

Ionic bonding definition?

Answer 5

The strong electrostatic attraction between positive and negative ions.

Question 6

What does ‘Electrostatic attraction’ mean?

Answer 6

Means that positively charged particles attract negatively charged particles.

Question 7

What does ‘isoelectronic’ mean?

Answer 7

Means ‘have the same number of electrons’

Question 8

Zinc (Ion) formula?

Answer 8

Zn²⁺

Question 9

Silver (Ion) formula?

Answer 9

AG⁺

Question 10

Hydrogen (Ion) formula?

Answer 10

H⁺

Question 11

Ammonium (Ion) formula?

Answer 11

NH₄⁺

Question 12

Nitrate (Ion) formula?

Answer 12

NO₃⁻

Question 13

Hydroxide (Ion) formula?

Answer 13

OH⁻

Question 14

Carbonate (Ion) formula?

Answer 14

CO₃²⁻

Question 15

Sulfate (Ion) formula?

Answer 15

SO₄²⁻

Question 16

What do all ionic compounds form?

Answer 16

They form crystals that consist of lattices of positive and negative ions packed in a regular way. The lattice is held together by the strong electrostatic attractions between the positively and negatively charged ions.

Question 17

What is a lattice?

Answer 17

It is a regular array of particles.

Question 18

What is a giant ionic lattice?

Answer 18

Giant meaning there are no individual molecules. There is no limit to the number of particles present.

Question 19

Why do ionic compounds have high melting and boiling points?

Answer 19

A lot of energy is required to break the strong electrostatic forces of attraction between oppositely charged ions in the giant lattice structure.

Question 20

Why are ionic crystals brittle?

Answer 20

Any small distortion of a crystal brings ions with the same charge alongside each other.

Question 21

List physical properties of ionic substances?

Answer 21

• High melting and boiling points.
• Ionic compounds tend to be crystalline.
• Ionic crystals tend to be brittle.
• Tend to be soluble in water.
• Tend to be insoluble in organic solvents.

Question 22

What does molten mean?

Answer 22

Means that the salt has been melted?

Question 23

Why don’t ionic compounds conduct electricity when they are solid?

Answer 23

Because the ions are fixed in position and are not free to move around.

Question 24

Why do ionic compounds conduct electricity when they are molten or dissolved in water?

Answer 24

Because the ions become free to move around.

Question 25

When do ionic compounds conduct electricity?

Answer 25

When they are molten or if they are dissolved in water (aqueous solution).

Question 26

What is a covalent bond?

Answer 26

A pair of electrons is shared between two atoms. The atoms are held together by the strong electrostatic attraction between the nuclei of the atoms and the shared pair of electrons.

Question 27

What is a simple molecular structure?

Answer 27

A substance which consists of molecules with intermolecular forces of attraction between them.

Question 28

Why do substances with simple molecular structures tend to have low melting and boiling points?

Answer 28

Because not much energy is required to break the weak intermolecular forces of attraction between molecules.

Question 29

Physical properties of covalent molecular compounds?

Answer 29

- Low melting and boiling points. - Don't conduct electricity. - Tend to be insoluble in water. - Often soluble in organic solvents.

Question 30

Why don't covalent molecular compounds conduct electricity?

Answer 30

Because the molecules don't have an overall electrical charge and electrons are held tightly in the atoms or covalent bonds so not able to move from molecule to molecule.

Question 31

Examples of simple molecular structures?

Answer 31

- H₂O - CO₂ - CH₄

Question 32

Why do substances with giant covalent structures have a very high melting and boiling point?

Answer 32

A lot of energy is required to break the very strong covalent bonds which extend throughout the structure.

Question 33

Why doesn't diamond conduct electricity?

Answer 33

All the electrons in the outer shells of the carbon atoms are held tightly in covalent bonds between the atoms. None are free to move around.

Question 34

Why is graphite a soft material?

Answer 34

Graphite has a layer structure and the layers slide over each other and can easily be flaked off.

Question 35

Why does graphite conduct electricity?

Answer 35

Some electrons are free to move throughout the layers. The movement of these delocalised electrons allows graphite to conduct electricity.

Question 36

What does a metallic structure consist of?

Answer 36

It consists of a lattice of positive ions in a sea of delocalised electrons.

Question 37

What is metallic bonding?

Answer 37

The electrostatic forces of attraction between each positive ion and the delocalised electrons.

Question 38

What type of structure do metals have?

Answer 38

Giant structures.

Question 39

Why do metals conduct electricity?

Answer 39

Because the delocalised electrons are free to move throughout the structure?

Question 40

What does malleable mean?

Answer 40

'Can be hammered into different shapes'

Question 41

Why are metals malleable and ductile?

Answer 41

When we apply a force to a piece of metal, the layers of positive ions slide over each other.

Question 42

What does ductile mean?

Answer 42

'Can be drawn out into wires'

Question 43

What is an alloy?

Answer 43

A mixture of a metal with other metals (or carbon).

Question 44

Why are alloys harder than the individual pure metals from which they are made?

Answer 44

The different metals/elements have differently sized atoms. This makes it more difficult for the layers of ions to slide over each other.

Question 45

Examples of common alloys?

Answer 45

- Bronze (mixture of copper and tin) - Brass (mixture of copper and zinc) - Steel (alloy of iron and carbon)

Question 46

Ethene formula?

Answer 46

C₂H₄

Question 47

Ethane formula?

Answer 47

C₂H₆