Metals

Question 1

When was the copper age ?

Answer 1

It was between 3200-2300BC

Question 2

When was the Bronze Age?

Answer 2

The Bronze Age was after the copper age and spanned between 2300-700BC

Question 3

When was the Iron Age?

Answer 3

The Iron Age was an era that began after the Bronze Age and lasted from 700BC- AD 1

Question 4

Outline some uses of bronze during the Bronze Age?

Answer 4

Used for tools, weapons, armour, building materials

Question 5

What were some uses of copper during the copper age?

Answer 5

Tools, weapons, jewellery, ornaments, domestic utensils

Question 6

Why is energy input required to extract a metal from its ore?

Answer 6

Many ores contain metal oxides. Metal oxides are ionic substances with strong ionic bonds that keep it together. In order to separate the metal from its ore it must be subjected to high temperatures in order for the oxide to decompose and to separate into its individual components

Question 7

What are some uses of brass and why does it have these uses?

Answer 7

Brass is most commonly used in plumbing fittings, musical instruments and decorations

It used for these purposes due to it lustrous gold appearance and its ability to be easily machined and its strength

Question 8

What is brass made out of?

Answer 8

50-60% copper with zinc metal

Question 9

What are some uses of solder and why does it have these uses?

Answer 9

Solder is used to join metals together , particularly in plumbing and electronics

It’s used in this manner due to its low melting point and its ability to adhere to other metals when in molten form

Question 10

What is solder made from?

Answer 10

Solder consists of 30-60% tin with lead

Question 11

Name some uses of stainless steel?

Answer 11

Stainless steel is used for food processing machinery, kitchen sinks and appliances, cutlery, surgical and dental instruments, some razor blades

Question 12

Why is stainless steel used in this way?

Answer 12

Stainless steel is corrosion resistant and very strong. It’s uses require it to be cleaned regularly as it is used for cutlery, surgical equipment, kitchen appliances etc, and so as it is corrosion resistant, it will not rust when in the presence of water

Question 13

What is stainless steel made from?

Answer 13

Iron with 10-20% chromium, and 5-20% nickel

Question 14

What is a mineral?

Answer 14

Any naturally occurring chemical element or compound in the earths crust. Most minerals are crystalline solids whose chemical composition is constant

Question 15

What is an ore and what makes it an ore?

Answer 15

An ore is an aggregate of minerals from which one or more materials can be extracted profitably. Therefore a mineral at a particular place may be an ore or may not be an ore at a later stage

Questions to consider when determining if a mineral is an ore are

1. Is it valuable? Referring to the metal that is being extracted
2. Does it existed in concentration worth mining, milling and transporting for profits
3. is the metal easily extractable from crushed rock using mineral processing techniques

Question 16

Recount the steps in the recycling of aluminium

Answer 16

1. Consumers dispose of aluminium foil and cans in a recycling bin
2. These contents then get transported to a treatment plant where they are cleaned
3. These contents then go through a re-melt process which returns the aluminium to a molten state, removing any inks, labels or other impurities
4. Molten aluminium is made into large ingots which are then sent to a mill and made into sheets
5. Metal sheets are then made into cans and foil again and sent back to the shops in about 6 weeks

Question 17

Why is energy required to extract a metal from its ore?

Answer 17

1. To seperate and thus break strong ionic bonds between metals and their combined elements
2. Also required to break down these ores

Question 18

Why is it better to recycle aluminium then to extract it from its ore?

Answer 18

1. Less energy is used to recycle the aluminium as compared to if it were extracted from ore
2. The process involved a much cheaper as there are less expenses involved
3. Recycling metals is better for the environment as less pollutants are released into the atmosphere and compared to if aluminium was smelted and refined from ore

Question 19

Explain why there are more metals around for use today then there were 200 years ago?

Answer 19

1. Limited knowledge of chemistry in terms of electrolyse as compared to today
2. It was very expensive to extract, for instance, aluminium using electrolysis
3. Some of the most important discoveries in terms of mineral prospecting occured in the last 200 years, for example iron in Australia and gold in South America

Question 20

recount gay-lussacs law

Answer 20

guy-lussac studied the properties and reactions of gases. he found that :

volumes of gases taking part in a chemical reaction show simple whole number ratios to one another, when measured at the same temperature and pressure.

Question 21

recount avagadros law

Answer 21

equal volumes of all gases at the same temperature and pressure contain equal numbers of particles

Question 22

what is a half equation?

Answer 22

equations which show the loss or gain of electrons by an atom, forming an ion.

Question 23

what is ionization energy and what is the trend in ionization energy in the periodic table?

Answer 23

First ionisation energy is the energy required to remove one electron from an atom in the gas phase. Moving down Group I of the Periodic Table the valence shell is further and further from the nucleus, and more shielded from its positive charge by full inner shells. As a result the valence electron is held less and less strongly, requiring less and less energy to remove it. Hence the first ionisation energy decreases moving down Group I.

Question 24

what is electronegativity and what is the trend in electronegativity in the periodic table?

Answer 24

Electronegativity is an atom’s affinity for or attraction to an electron. Moving down Group VII the valence shell is also further and further from the nucleus, and shielded from its positive charge by an increasing number of full inner shells. The valence shell of atoms in Group VII requires one extra electron to be full, but because the valence shell is less and less attracted to the nucleus, this extra electron is attracted less and less strongly moving down the group. Hence the electronegativity decreases moving down the group.

Question 25

what happens first in the extraction of copper and what does it involve?

Answer 25

1. Mining

- ore is extracted from the mine, transported to primary crushers

Question 26

what happens after mining the copper?

Answer 26

2. Milling
   - ore crushed and screened
   - fine sulfide is place in froth flotation cells where Cu attaches to chemical bubble
   - forms Cu Concentrate about 18-45% Cu

Question 27

what happens after milling the copper?

Answer 27

3. Smelting
   - heated in an oven at 1200 degrees with air and silicon flux.
   - reaction is rapid and produces a copper matte
   - impurities of iron oxides and sulfides converted to slag. discarded and used to refill mine
   - sulfur removed by blowing air at it at high speeds
   - blister copper forms, 98%, place in furnace to remove O2
   - poured into anode mold and shipped to refinery

Question 28

what happens after smelting the copper?

Answer 28

4. Refinery
   - electrolysis: impure copper anodes placed in electrolysis cells with an acidic copper sulfate solution
   - anode dissolved and very pure copper is deposited on the cathode
   - impurities either go into solution or faill to the bottom as anode mud, contains nonreactive meals which can be extracted themselves