Chapter 3- Structure And Bonding

Question 1

What are the three states of matter?

Answer 1

Solid, Liquid, Gas

Question 2

The particles in a solid are…

Answer 2

They are packed closely together and vibrate around fixed positions

Question 3

The particles in a liquid are…

Answer 3

The particles in a liquid are packed closely together but can slip and slide over each other in random motion

Question 4

The particles in a gas are…

Answer 4

The particles in a gas on average have a lot of space between them and zoom around freely

Question 5

What charge will a group 6 and group 2 element form?

Answer 5

Group two will form two plus

Group six will form two minus

Question 6

How do elements form compounds?

Answer 6

By gaining or losing electrons or sharing electrons

Question 7

What combinations of groups can form ionic compounds

Answer 7

7
1
6
2

Question 8

What are ionic compounds held together by?

Answer 8

They are held together by strong forces of attraction between their oppositely charged ions. This is called ionic bonding.

Question 9

What happens when metals form ions?

Answer 9

They lose electrons from their outer shell to form positive ions

Question 10

What happens when non metals form ions?

Answer 10

They gain electrons in their outer shell to form negative ions

Question 11

What charge would the ions in group 1,2,6 and 7 have?

Answer 11

1, +1
2, +2
6, 2-
7, 1-

Question 12

Name 3 properties of ionic compounds

Answer 12

They have high melting and boiling points due to the many strong electrostatic attractions.
When ionic compounds are solid they are held in place and don’t conduct electricity when they are melted they are able to conduct electricity because the atoms are free moving.
Ionic compounds dissolve easily in water. When dissolved they conduct electricity

Question 13

What is the empirical formula?

Answer 13

You will be given a structure and asked to look at the charges and work out the formula for the two atoms

Question 14

What kind of atoms covalent bond?

Answer 14

Non metals

Question 15

Describe the simple molecular bond of hydrogen

Answer 15

Hydrogen atoms have just one shell they only need one more to complete the first shell. The covenant bond consists of two hydrogen atoms

Question 16

Describe the simple molecular bond of chlorine

Answer 16

Each chlorine atom only needs one more electron to complete the outer shell. So two chlorine atoms form a single covenant bond

Question 17

Describe the simple molecular bond of oxygen

Answer 17

Only needs two more electrons.

Two oxygen atoms share two pairs of electrons making a double covalent bond

Question 18

Describe the simple molecular bond of nitrogen

Answer 18

Nitrogen atoms need three more electrons.

So two nitrogen atoms share three pairs of electrons, it creates a triple bond

Question 19

Describe the simple molecular bond of methane

Answer 19

It forms 4 covenant bonds with hydrogen

Question 20

Describe the simple molecular bond of water

Answer 20

In water molecules the oxygen forms two covenant bonds with hydrogen forming two single covalent bonds

Question 21

Is the melting point high or low of simple molecular substances

Answer 21

It’s low because the forces between the molecules is weak not the force between the atoms

Question 22

Do molecular compounds conduct electricity, why?

Answer 22

They don’t because they aren’t charged

Question 23

What state are most molecular substances at room temperature?

Answer 23

Most are either liquid or gas

Question 24

Why is a polymer?

Answer 24

It’s lots of small units that are linked together to form a long molecule that has repeating sections. All of the atoms in a polymer are joined by covenant bonds .

Question 25

What state are polymers at room temperature?

Answer 25

They have strong molecular bonds so most are solid.

Question 26

Describe the melting and boiling points of polymers

Answer 26

The bonds are still weaker than ionic and giant molecular compounds so they have a lower boiling point then them

Question 27

Give 3 properties of giant covenant structures

Answer 27

All the atoms are bonded to each other by strong covenant bonds.
They have high melting and boiling points.
They don’t contain charged particles so they don’t conduct electricity

Question 28

Describe the structure of a diamond giant structure

Answer 28

Each carbon atom forms 4 covenant bonds in a very rigid giant covalent structure. It has a very high melting point. It doesn’t conduct electricity because it has no free electrons or ions

Question 29

Describe the structure of a graphite giant structure

Answer 29

Each carbon atom forms thee covenant bonds to create layers of hexagons. Each carbon atom also has one delocalised electron. There is no strong bonds between the layers of hexagons so they slide over each other. It has got a high melting point. It is an exception and conducts thermal and electrical energy

Question 30

Describe what silicon dioxide is

Answer 30

It is sand and Is made up of silicon and oxygen

Question 31

What is graphene?

Answer 31

Graphene is a sheet of carbon dioxide joined together in hexagons the sheet is just one atom thick. The multiple connections make it very strong. It’s also incredibly light so can be added to materials to improve their strength. It can conduct electricity

Question 32

Why can graphite conduct electricity?

Answer 32

Because only three out of carbons 4 outer electrons are used in bonds so each carbon atom has one electron that is delocalised .

Question 33

What are fullerenes?

Answer 33

Fullerenes are molecules of carbon shaped like closed tubes or hollow balls.

Question 34

Describe a fullerene

Answer 34

They’re mainly made up of carbon atoms arranged in hexagons but can contain pentagons and heptagons.
Fullerenes can be used to cage and hold other molecules
Fullerenes have a huge surface area

Question 35

Give three uses of fullerenes

Answer 35

They can be used to deliver drugs into the body via encasing the drug.
They can form nanotubes
They make great lubricants

Question 36

What are nanotubes?

Answer 36

Fullerenes from nanotubes, tiny carbon cylinders.
The ratio between the length and the diameter is high.
They can conduct both electrical and thermal energy.
They have a high tensile strength.
They are used because they are strong but very light

Question 37

What is the buckminsterfullerene?

Answer 37

It is the first fullerene to be discovered the formula is C60 and forms a hollow there

Question 38

What are delocalised electrons?

Answer 38

The electrons in the outer shell of the metal atom are delocalised there are strong connections between the positive metal ions and the shared negative electrons

Question 39

Describe the melting point of metals metallically bonded

Answer 39

The forces between the metal atoms and the delocalised sea of electrons are very strong and are hard to break. It means most compounds with metallic bonds have very high melting points and are generally solid at room temperature.

Question 40

Are metals good conductors of energy? Why?

Answer 40

Yes they conduct electricity well because of the delocalised electrons carrying the current throughout the whole structure

Question 41

Are metals malleable?why?

Answer 41

They are because the layers of atoms slide over each other, it means they can be shaped relatively easily

Question 42

Are alloys malleable?why?

Answer 42

They aren’t because the introduction of a different metal obstructs the regular and uniform formation of atoms in a metal and means that the atoms cannot slide over each other very well

Question 43

What are alloys?

Answer 43

They are metals that have been combined with other metals or elements to create stronger metals, they are harder and are therefore more useful than regular metals

Question 44

4 key words to remember when describing a change of state

Answer 44

Melting
Boiling

Freezing
Condensing