C2

Question 1

Who made the first proper Periodic Table?

Answer 1

Dmitri Mendeleev.

Question 2

What did creator of the first Periodic Table do?

Answer 2

He left gaps for undiscovered elements.

Question 3

How many outer shell electrons are in oxygen?

Answer 3

6.

Question 4

In which group and period of the table would you find the element with electronic structure 2.8.8.2?

Answer 4

Group 2 and Period 4.

Question 5

Why does Ionic bonding occur?

Answer 5

For the elements to obtain a full outer shell.

Question 6

What ions do Ionic bonds include?

Answer 6

Ions with opposite charges.

Question 7

Give examples of the properties ionic bonds have.

Answer 7

• high melting and boiling points
• molten phase can move and conduct electricity
• dissolve easily in water

Question 8

How do Covalent bonds obtain a full outermost shell?

Answer 8

By sharing electrons.

Question 9

What are the properties of covalent bonds?

Answer 9

• atoms within molecules are held together by strong electrostatic force
• forces of attraction between molecules are weak
• -> low melting and boiling points
• don’t conduct electricity

Question 10

Give two similarities and differences between Diamond and Graphite, in terms of their structure and properties.

Answer 10

Similarities: Made by Carbon Atoms, high melting points
Differences: Graphite can conduct electricity and graphene slide past each other,, delocalized electrons can move.

Question 11

State the size of nanoparticles.

Answer 11

1-100 nanometers.

Question 12

Explain the benefits of nanoparticles having a high surface area to volume ratio.

Answer 12

A larger proportion of their atoms can react with the substances they come into contact with.

Question 13

Give three examples of the use of nanoparticles.

Answer 13

Any 3 of the following: Sunscreen, deodorants, nanomedicine, lubricant coatings, surgical masks, wound dressings.

Question 14

What are polymers?

Answer 14

Lots of small molecules called monomers joined together.

Question 15

Describe the properties of metals.

Answer 15

-high melting/ boiling point, good conductors of electricity

Question 16

Copper is a metallic element. State what property of copper makes it suitable for using in electrical circuits, and explain why it has this property.

Answer 16

Copper has a sea of delocalised electrons which move freely through the metal, carrying the electric charge.

Question 17

Is the boiling point of metallic structures high or low?

Answer 17

High.

Question 18

Ally buys a carton of juice labelled ‘100% pure apple juice’. Decide whether the use of the word ‘pure’ matches the scientific definition.

Answer 18

No. As apple juice consists of water, sugar and other substances, it is a mixture of different substances and is therefore impure.

Question 19

Steel is produced by adding carbon to iron to make it stronger. Would you expect steel to have a higher or lower melting point than pure iron?

Answer 19

Lower. Impure substances create a lower melting/ boiling point in comparison to pure substances.

Question 20

What type of distillation could you use to separate a mixture of liquids?

Answer 20

Fractional distillation.

Question 21

Substance A, B and C have boiling points of 97, 65 and 78 degrees. Suggest a method to separate the mixture and put the order of collection from first to last.

Answer 21

Fractional distillation.

B - C - A.

Question 22

A student is given a solution made by copper sulfate crystals in water. Describe a method that they could use to extract pure copper sulfate crystals from the solution.

Answer 22

Crystallisation. Pour the solution into an evaporating dish and gently heat the solution. The solvent will evaporate and the solution will become more concentrated. Once crystals start to form leave the dish to cool, filter and leave them in a warm place to dry.

Question 23

How is Thin Layer Chromatography different from Paper Chromatography?

Answer 23

The stationary phase of Paper Chromatography is paper instead of a thin layer of solid.

Question 24

How can you calculate the Rf value for each chemical?

Answer 24

Rf = distance travelled by solute/ distance travelled by solvent

Question 25

How can you interpret gas chromatograms and identify gases?

Answer 25

By observing the retention time- amount of time it takes a chemical to travel through the tube.

Question 26

What is relative atomic mass?

Answer 26

The relative atomic mass of an element is the average mass of one atom of the element, compared to 1/12 of the mass of one atom of carbon-12

Question 27

What is an empirical formula?

Answer 27

The simplest ratio of atoms.