Unit 3 - Topic 1 - Metals

Question 1

Do metals have a high or low density and why?

Answer 1

Metals have a high density indicating the metal atoms are closely packed together.
Except group 1

Question 2

Describe metallic bonding

Answer 2

The outer electron(s) on each atom are free to move between the atoms. This results in a regular arrangement (a LATTICE) of POSITIVE IONS with NEGATIVE ELECTRONS moving between the positive ions.

Question 3

Why are atoms in a metal said to be delocalised?

Answer 3

They are not located on a specific atom.

Question 4

Describe metal attraction

Answer 4

The electrostatic attraction between the positive ions and the delocalised electrons acts in all 3-dimensions, strongly holding the lattice together.

Question 5

Do metals have high or low melting and boiling points?

Answer 5

High

Question 6

Is metallic bonding strong or weak and why?

Answer 6

There is usually a large difference between the melting and boiling point of a metal (its liquid range). This indicates metallic bonding is very strong.

Question 7

Are metals bad or good conductors of heat and electricity and why?

Answer 7

Good. This is due to the presence of the delocalised electrons.

The movement of the delocalised electrons passes on the energy during conduction of heat.

Question 8

Describe the conduction of metals

Answer 8

During conduction of an electric current, electrons pushed into the metal from the NEGATIVE ELECTRODE of a battery or power supply make the delocalised electrons move towards the POSITIVE ELECTRODE.

The metal is not affected by the passage of an electric current, as the number of electrons always equals the number of protons in the lattice.

Question 9

How is metal reactivity measured?

Answer 9

The amount of energy given out when a metal reacts gives a measure of its reactivity.

Question 10

Describe metals and oxygen

Answer 10

All metals react with oxygen to make a METAL OXIDE.
Potassium permanganate (KMnO4) gives off oxygen when heated.
Different metals can be reacted with pure oxygen to observe how well the react.

Question 11

Describe an oxidation reaction

Answer 11

A reaction where a reactant loses an electron (or electrons) is called an OXIDATION REACTION.

When metals react their atoms lose electrons to form their ions. This means all metals undergo an OXIDATION REACTION when they react.

Question 12

Describe metals and acids

Answer 12

When a metal reacts with an acid the products are a SALT and HYDROGEN.

The speed of production of hydrogen gives a measure of the reactivity of the metal.

Question 13

Describe metals and water

Answer 13

When a metal reacts with water the products are a METAL HYDROXIDE solution (an alkali) and HYDROGEN.

Only metals from groups I (ALKALI METALS), and group II (ALKALINE EARTH METALS), react with water.

Question 14

Which metals don’t react

Answer 14

Silver (Ag)

Gold (Au)

Question 15

Which metals react with oxygen

Answer 15

Potassium (K)
Sodium (Na)						
Lithium (Li)						
Calcium (Ca)						
Magnesium (Mg)						
Aluminium (Al)					
Zinc (Zn)					
Iron (Fe)					
Tin (Sn)					
Lead (Pb)					
Copper (Cu)				
Mercury (Hg)

Question 16

Which metals react with acid

Answer 16

Potassium (K)
Sodium (Na)						
Lithium (Li)						
Calcium (Ca)						
Magnesium (Mg)						
Aluminium (Al)					
Zinc (Zn)					
Iron (Fe)					
Tin (Sn)					
Lead (Pb)

Question 17

Which metals react with water

Answer 17

Potassium (K)
Sodium (Na)						
Lithium (Li)						
Calcium (Ca)						
Magnesium (Mg)

Question 18

Describe MAZIT metals

Answer 18

The metals in the middle of the reactivity series are called the MAZIT metals.

They are the most commonly/often used metals

Question 19

Describe MAZIT

Answer 19

Magnesium (Mg)
Aluminium (Al)					
Zinc (Zn)					
Iron (Fe)					
Tin (Sn)

Question 20

Describe oxidation

Answer 20

When a metal reacts, the metal atoms lose electrons and change into metal ions. This is an OXIDATION REACTION.

The electrons lost from a metal atom during a reaction have to be GAINED by another reactant.

Question 21

Describe reduction

Answer 21

When a metal reacts, the metal atoms lose electrons and change into metal ions. This is an OXIDATION REACTION.

The electrons lost from a metal atom during a reaction have to be GAINED by another reactant.

Question 22

Where are the metals we use obtained from?

Answer 22

The Earth’s Crust

Question 23

Describe obtaining metals

Answer 23

Most metals are too reactive to exist in a pure uncombined form in the Earth’s crust. Metals are found in rocks as metal compounds. The usual metal compounds found in rocks are OXIDES, SULPHIDES and CARBONATES.

Question 24

Describe native metals

Answer 24

A few metals are found uncombined, as they are very unreactive. Metals, which are found uncombined, are called NATIVE METALS.

Question 25

Name the native metals

Answer 25

Gold (Au)
Platinum (Pt)
Silver (Ag)
Copper (Cu)

Question 26

Describe metal ores

Answer 26

Rocks, which contain metals or compounds of metals, are called ORES.

Question 27

What’s the link between reactivity and date of discovery?

Answer 27

The least reactive metals were discovered the earliest.

Question 28

Describe metal oxides

Answer 28

A large number of ores contain metal oxides.

To extract a metal from an ore requires heat. Some metal oxides break down by heat alone.

Question 29

Describe heating Silver (I) Oxide

Answer 29

Silver(I) oxide breaks down on heating to form silver and oxygen.

Silver(I) oxide decomposes on heating to form silver and oxygen.

Question 30

Describe heating Copper (II) Oxide

Answer 30

Heating has no effect on copper(II) oxide.

Question 31

Describe a decomposition reaction

Answer 31

Breaking down a compound into its elements from which it is made is called a DECOMPOSITION REACTION.

Question 32

Describe metal oxides with carbon

Answer 32

Metals with very low reactivity can be extracted by just heating their compounds.

Copper is too reactive to be extracted by HEAT ALONE.

Metals with low to middle reactivity can be extracted by heating their compounds with carbon.

Question 33

Describe carbon reduction

Answer 33

Zinc (Zn), Iron (Fe), Tin (Sn), Lead (Pb) and Copper (Cu) are extracted using carbon or carbon monoxide. This method of extraction is called carbon reduction.

Question 34

Describe the results after heating Copper (II) Oxide with Carbon

Answer 34

After the reaction some orange / brown copper can be seen in the beaker.

The products of the reaction are COPPER and CARBON DIOXIDE

Carbon helps remove the oxygen from the copper(II) oxide. The oxygen transfers to the carbon forming carbon dioxide.

Question 35

Describe the extraction of aluminium

Answer 35

Aluminium is too reactive to extract by heating with carbon or carbon monoxide.

All reactive metals from aluminium upwards on the reactivity series are extracted using ELECTROLYSIS.

Question 36

Describe alumina

Answer 36

The bauxite ore is purified to produce pure aluminium oxide Al2O3.

Alumina is dissolved in molten cryolite (Na3AlF6), as it has a lower melting point than aluminium oxide, which reduces the energy needed for the extraction.

This solution is electrolysed and molten aluminium metal forms at the negative electrode.

Question 37

Which metals can be extracted by heat alone or found uncombined (LR-MR)?

Answer 37

Platinum
Gold
Silver

Question 38

Which metals can be extracted by heat with carbon (LR-MR)?

Answer 38

Copper
Lead
Tin
Iron
Zinc

Question 39

Which metals can be extracted by electrolysis (LR-MR)?

Answer 39

Aluminium
Magnesium
Calcium
Lithium
Sodium
Potassium