C2.1 Structure and Bonding

Question 1

What is formula of a chloride ion?

Answer 1

Cl^-

Question 2

Why do ionic compounds have high melting and boiling points?

Answer 2

They have strong electrostatic attractions between oppositely charged ions. These take a lot of energy to overcome so they have high melting and boiling points.

Question 3

How many electrons can go in the second and third electron shells?

Answer 3

8

Question 4

What is ionic bonding?

Answer 4

It is where a metal and non-metal bond by transferring electrons from the metal to the non-metal.

Question 5

What type of substance forms negatively charged ions?

Answer 5

A Non-metal

Question 6

What is an ion?

Answer 6

An ion is a charged atom.

Question 7

What is the formula of sodium ion?

Answer 7

Na+

Question 8

Why do simple covalent molecules have low melting and boiling points?

Answer 8

The forces of attraction between molecules (intermolecular forces) are weak so do not require much energy to overcome them.

Question 9

An element has atomic number 17. What is its electron arrangement?

Answer 9

2,8,7

Question 10

Are the melting points of giant covalent substances very high or very low?

Answer 10

Very high as it takes a lot of energy to break the strong covalent bonds in the lattice.

Question 11

A metal ion loses 2 electrons what charge does it have?

Answer 11

+2

Question 12

Does diamond conduct electricity?

Answer 12

No, as it has no free electrons since each carbon atom forms 4 bonds.

Question 13

What type of substance loses electrons and forms positively charged ions?

Answer 13

Metals

Question 14

What is the overall charge of an ionic compound?

Answer 14

0

Question 15

What are the ions held in place by?

Answer 15

Strong electrostatic attractions between oppositely charged ions.

Question 16

An element has an electron arrangement of 2,8,8 which group is it in?

Answer 16

It is in group 0 or group 8 as it has a full outer shell.

Question 17

Why do ionic compounds not conduct electricity when solid?

Answer 17

The ions are not free to move.

Question 18

Which type of substances bond covalently?

Answer 18

Non-metals only.

Question 19

A non-metal atom loses one electron. What is the charge on the ion formed?

Answer 19

-1

Question 20

Give three examples of giant molecular substances

Answer 20

Silicon dioxide ( sand), diamond, graphite

Question 21

Whats the difference between ionic and covalent bonding?

Answer 21

Ionic bonding is the transfer of electrons whereas covalent is the sharing of electrons.

Question 22

Why do noble gases not form compounds easily?

Answer 22

They have full outer shells of electrons.

Question 23

Give three examples of simple covalent molecules.

Answer 23

Water, carbon dioxide and methane

Question 24

How many electrons can go in the first electron shell?

Answer 24

2

Question 25

What are the typical properties of ionic substances?

Answer 25

They have high melting and boiling points and conduct electricity when molten or in aqueous solution.

Question 26

When do atoms turn into ions?

Answer 26

When they lose or gain an electron.

Question 27

What happens when a metal and non- metal ionically bond?

Answer 27

The metal transfers electrons to the non-metal and becomes positively charged. The non-metal becomes negatively charged.

Question 28

An element has atomic number 8 what is the electron arrangement?

Answer 28

2,6

Question 29

Are the melting points of ionic substances very high or very low?

Answer 29

High

Question 30

Why does graphite conduct electricity?

Answer 30

Each carbon atom only forms 3 bonds instead for 4. So it has delocalised electrons between the layers of carbon atoms which are free to move and pass a current.

Question 31

True or false? Graphite is softer than diamond.

Answer 31

True, this is because graphite has layers of carbon atoms that can slide over each other easily as they are only held together by weak intermolecular forces.