Covalent Bonding

Question 1

Why do elements combine to make compounds?

Answer 1

To achiever a full outer shell

Question 2

What are the 4 main types of structures that can be created by combining atoms?

Answer 2

Covalent molecular
Covenant network
Giant ionic lattice
Metallic lattice

Question 3

What is a covalent bond?

Answer 3

When two or more non-metal atoms share a pair of electrons (or more).

Question 4

What is a diatomic molecule?

Answer 4

A molecule only containing two types of atoms.

Question 5

What are the seven diatomic molecules?

Answer 5

Bromine
Iodine
Nitrogen
Chlorine
Hydrogen
Oxygen
Fluorine

Question 6

What is a molecule?

Answer 6

Atoms that share pairs of electrons dork molecules. A molecule is a group of atoms held together by covalent bonds.

Question 7

What are the shapes of covalent molecules?

Answer 7

Linear
Angular
Trigonal Pyramidal
Tetrahedral

Question 8

What are intermolecular forces?

Answer 8

The covalent bonds between the atoms in a molecule are very strong but in a covalent molecular substance, there are also much weaker forces which exist between each molecule.

Question 9

What is the intermolecular attraction?

Answer 9

The very weak forces between molecules

Question 10

What is the intramolecular forces?

Answer 10

The very strong forces inside molecules between atoms.

Question 11

What is a covalent network?

Answer 11

A covalent network structure consists of a giant 3-dimensional lattice of covalently bonded atoms.

Question 12

What 3 atoms are examples of covalent network structure elements?

Answer 12

Boron
Carbon
Silicon

Question 13

What are four examples of covalent networks?

Answer 13

Diamond
Graphite
Silicon dioxide
Silicon carbide

Question 14

Two properties of diamond

Answer 14

Tetrahedral shape
Uses all 4 carbon bonds

Question 15

Two properties of graphite

Answer 15

Flat layers
Only uses 3 carbon bonds (so delocalised electrons conduct electricity)

Question 16

What do some covalent substances exist as?

Answer 16

Discrete molecules (individual)

Question 17

What happens to the melting and boiling points if the bonds are weak?

Answer 17

They are easily broken and require little energy to do so.

Question 18

How strong are the bonds holding the molecules together in discrete molecules?

Answer 18

Weak

Question 19

How string are the bonds holding the atoms to geehrte in the network structures?

Answer 19

Very strong

Question 20

What happens to the melting and boiling points if the bonds are very strong?

Answer 20

Extremely high

Question 21

What state do metals have to be in tho conduct electricity?
And what are their melting and boiling points?

Answer 21

Solid + liquid
High

Question 22

In what state do non-metals conduct electricity?
And what are their melting and boiling points?

Answer 22

They don’t
Low

Question 23

In what state do ionic compounds conduct electricity?
And what are their melting and boiling points?

Answer 23

Liquid and when dissolved in water
High

Question 24

In what state do covalent molecular conduct electricity?
And what are their melting and boiling points?

Answer 24

They don’t
Low

Question 24

In what state do covalent networks conduct electricity? And what are their melting are boiling points?

Answer 24

They don’t High

Question 25

What are the exceptions to the conductivity rules?

Answer 25

Mercury (metal)- a liquid metal Graphite- a conducting non-metal

Question 26

Is sulphur soluble in water and hexane?

Answer 26

Water- no Hexane- no

Question 27

Is wax soluble in water and hexane?

Answer 27

Water- no Hexane- yes

Question 28

Is sucrose soluble in water and hexane?

Answer 28

Water- yes Hexane- no

Question 29

Is ethanol soluble in water and hexane?

Answer 29

Water- yes Hexane- yes

Question 30

What are the solubility of covalent substances?

Answer 30

Some are soluble in water Others are soluble in solvents such as Hexane

Question 31

Does wax is solid or liquid conduct electricity?

Answer 31

No

Question 32

Does sand when a solid conduct electricity?

Answer 32

No

Question 33

Do covalent molecular or covalent networks conduct electricity?

Answer 33

No

Question 34

Two properties of covalent molecular substances

Answer 34

Low melting and boiling points Weak forces between molecules

Question 35

Two properties of covalent molecular substances

Answer 35

Very High melting and boiling points Strong bonds between atoms

Question 36

What is the solubility of most covalent molecular substances?

Answer 36

Insoluble in water Soluble in non-aqueous solutions

Question 37

Solubility of covalent networks

Answer 37

Insoluble in all solvents

Question 38

Conductivity of covalent molecular substances and why and exceptions

Answer 38

Never conduct electricity in any state because they contain no free electrons however there is an exception for graphite as it conducts electricity due to delocalised electrons.