Structure and bonding

Question 1

What are ions and how are the formed?

Answer 1

Ions are electrically charged particles that are formed when atoms lose or gain electrons.

Question 2

Why is the structure of an ion similar to a noble gas?

Answer 2

The loss or gain of electrons leaves a full highest energy level.

Question 3

What happens to metal atoms when they become ions?

Answer 3

Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions.

Question 4

What happens to non-metal atoms when they become ions?

Answer 4

Non-metal atoms gain an electron, or electrons, from another atom to become negatively charged ions.

Question 5

How can you work out the number of charges on a metal ion? (+1, +2, +3 etc.)

Answer 5

The number of charges on an ion formed by a metal is equal to the group number of the metal.

Question 6

How would you draw the electronic structure of a sodium ion, 2,8,1?

Answer 6

Get rid of the last one and put it in brackets (wedding bands) and put a + in the top corner, so it becomes (2,8)+

Question 7

How would you draw the structure of an oxygen ion? 2,6

Answer 7

Add two dots and put it in brackets, with 2- at the top.

Question 8

How is an ionic compound formed?

Answer 8

When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms, forming ions, forming an ionic compound.

Question 9

What are the forces of an ionic bond like?

Answer 9

There is a strong electrostatic force of attraction between these oppositely charged ions, called an ionic bond.

Question 10

What are the elements in group one called?

Answer 10

The alkali metals

Question 11

What charge do the alkali metals form when they react with non-metals?

Answer 11

Their ions have a single positive charge.

Question 12

When is a covalent bond formed?

Answer 12

A covalent bond forms when two non-metal atoms share a pair of electrons.

Question 13

What are the properties of covalent bonds?

Answer 13

Covalent bonds are strong - a lot of energy is needed to break them.
Low melting and boiling points

Question 14

How can you work out the number of bonds in a covalent bond?

Answer 14

8 minus the group number.

Question 15

What are the properties of simple molecular substances?

Answer 15

Low melting and boiling points - This is because the weak intermolecular forces break down easily.
Non-conductive - Substances with a simple molecular structure do not conduct electricity. This is because they do not have any free electrons or an overall electric charge.

Question 16

What are macromolecules?

Answer 16

Macromolecules have giant covalent structures, their atoms are arranged into giant lattices.

Question 17

What are the properties of diamond?

Answer 17

Diamond is a giant covalent structure.

As a result, diamond is very hard and has a high melting point. It does not conduct electricity.

Question 18

Why is graphite softer than diamond?

Answer 18

Graphite is soft and slippery because there are only weak intermolecular forces between its layers.

Question 19

What is a polymer?

Answer 19

A large molecule formed from many smaller molecules called monomers.

Question 20

What are thermosoftening polymers?

Answer 20

Thermosoftening polymers soften when heated and can be shaped when hot.
The shape will harden when it is cooled, but can be reshaped when heated up again.

Question 21

Why can thermosoftening polymers be heated and re-shaped?

Answer 21

Because its tangles polymer chains can uncoil and slide past each other.
The polymer has no cross links.

Question 22

Whats the difference between thermosetting polymers and thermosoftening polymers?

Answer 22

Thermosetting polymers have different properties to thermosoftening polymers. Once moulded, they do not soften when heated and they cannot be reshaped.

Question 23

Give an example of a thermoset?

Answer 23

Vulcanised rubber which is used to make tyres.

Question 24

Why can’t thermosetting polymers be re-shaped?

Answer 24

Because its polymer chains are joined together by cross-links, so they cannot slide past each other easily.

Question 25

What are the properties of ionic compounds?

Answer 25

High melting and boiling points,
Ionic compounds conduct electricity when they are dissolved in water or when they are melted,
Strong bonds.

Question 26

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

Answer 26

This is because their ions cannot move around in their lattice structure.

Question 27

Why are metals malleable?

Answer 27

This is because they consist of layers of atoms. These layers can slide over one another when the metal is bent, hammered or pressed.

Question 28

Why are metals good conductors?

Answer 28

Metals are good conductors of electricity and heat. This is because the free electrons can move throughout the metal.

Question 29

What are the properties of metals?

Answer 29

High melting and boiling points,

Good conductors of electricity and heat.

Question 30

Whats an alloy?

Answer 30

An alloy is a mixture of two or more elements, where at least one element is a metal.

Question 31

Why are alloys harder than pure metals?

Answer 31

Alloys contain atoms of different sizes.
These different sizes distort the regular arrangements of atoms.
This makes it more difficult for the layers to slide over each other.

Question 32

What might nanoparticles be used in?

Answer 32

Sun screens and deodorants,
Catalysts,
Coatings

Question 33

Why is graphite a good conductor of heat and electricity?

Answer 33

Because graphite contains delocalised electrons.

Question 34

Carbon exists as graphite and diamond but it can also form fullerenes, what are fullerenes?

Answer 34

These are cages and tubes with different number of carbon atoms.

Question 35

What kay fullerenes be used in?

Answer 35

Fullerenes may be used for drug delivery systems in the body, in lubricants and as catalysts.