Uses of Metals

Question 1

do iron, aluminium and copper have the same basic properties?

Answer 1

yes

Question 2

what are the properties of iron, aluminium and copper?

Answer 2

• they are dense and lustrous (shiny) and have high melting points
• they have high tensile strength meaning they are strong and hard to break
• they can be hammered into a different shape (they are malleable)
• they are good conductors of electricity and of heat energy too

Question 3

what are the specific properties of iron?

Answer 3

• iron has all of the properties a metal would have except adding other materials to the iron can change its properties
• wrought iron is almost completely pure iron and its malleable so its used to make gates and railings
• the main problem with iron is that it corrodes easily

Question 4

what are the specific properties of aluminium?

Answer 4

• aluminium is also a typical metal however unlike iron, it doesn’t corrode easily
• aluminium reacts very quickly with oxygen in the air to form aluminium oxide - a nice protective layer of aluminium oxide sticks firmly to aluminium and stops any further reaction taking place
• because aluminium doesn’t corrode its useful for products that come in contact with water e.g. drink cans
• aluminium is also much less dense than iron, which makes it lighter
• this makes it useful when the weight of the metal is important e.g. in bicycle frames and airplanes

Question 5

what are the specific properties of copper?

Answer 5

• copper is an especially good conductor of heat and electricity
• it is used in electrical components and wiring as it has a low resistance and so is efficient at transferring electricity
• it is also used in heating systems, such as underfloor heating, as it allows speedy transfer of heat to the surroundings

Question 6

what is the problem with pure metals?

Answer 6

the regular structure of pure metals makes them soft - often too soft for use in everyday life

Question 7

how are alloys made?

Answer 7

by adding other elements to the metal

Question 8

why are alloys harder than pure metals?

Answer 8

• different elements have different sized atoms
• so when another element is mixed with a pure metal, the new atoms will distort the layers of metal atoms, making it more difficult for them to slide over each other - this makes alloys harder than pure metals

Question 9

what are steels?

Answer 9

alloys of iron - these are often used instead of pure iron and are made by adding small amounts of carbon and sometimes other metals to iron

Question 10

what is the alloy brass made from?

Answer 10

copper + zinc

Question 11

what is the alloy bronze made from?

Answer 11

copper + tin

Question 12

what is the alloy steel made from?

Answer 12

iron + carbon

Question 13

what elements are in the metal iron and what is its use?

Answer 13

elements = Fe

use = making steel - steel is more useful than iron

Question 14

what elements are in the alloy low-carbon steel and what is its use?

Answer 14

elements = Fe, 0.1% C

use = ships, cars, bridges - strong but low-carbon so can be hammered into various shapes

Question 15

what elements are in the alloy high-carbon steel and what is its use?

Answer 15

elements = Fe, 1% C

use = tools e.g. knives, screwdrivers - high-carbon so less malleable and stiffer than low-carbon steel

Question 16

what elements are in the alloy stainless steel and what is its use?

Answer 16

elements = Fe, 1% C, 10% Cr

use = cutlery, cooking utensils, kitchen sinks - Cr forms oxide layer that resists corrosion, so stays shiny and clean

Question 17

what elements are in the metal aluminium and what is its use?

Answer 17

elements = Cu

use:
wires - excellent conductor of electricity
cooking pans - excellent conductor of heat
water pipes - unreactive and malleable

Question 18

what elements are in the element aluminium and what is its use?

Answer 18

elements = Al

use:
aircraft bodies - low-density and high strength
power cables - low-density and conducts