metals

Question 1

what are the general physical properties of metals?

Answer 1

high melting and boiling point
good conductor of heat and electricity
malleable

Question 2

what happens in pure metals?

Answer 2

in pure metals, the atoms are of the same size and are packed in regular layers. hence, the layer of atoms can slide over each other easily when force is applied

Question 3

what are alloys?

Answer 3

alloys are a mixture of metal and one or more other elements
they do not have a fixed melting and boiling point

Question 4

what makes up steel and brass?

Answer 4

steel: iron and carbon
brass: copper and zinc

Question 5

do all elements have the same size?

Answer 5

no. different elements have different atom sizes. this disrupts the regular arrangement of the pure metal, and the atoms cannot slide over each other. hence, alloys are stronger and less malleable.

Question 6

what is the reactivity series abbreviation? (from most reactive to least)

Answer 6

please (potassium)
stop (sodium)
catching (calcium)
more (magnesium)
zebras (zinc)
i (iron)
like (lead)
having (hydrogen)
cute (copper)
short (silver)
giraffes (gold)

Question 7

what metals react with cold water?

Answer 7

potassium, sodium, calcium, magnesium

Question 8

what metals react with steam?

Answer 8

magnesium, zinc, iron

Question 9

what metals react with acids?

Answer 9

potassium, sodium, calcium, magnesium, zinc, iron, lead

Question 10

what metals are unreactive?

Answer 10

copper, silver, gold

Question 11

what are metal displacement reaction called?

Answer 11

they are called redox reactions
a more reactive metal can displace a less reactive metal from its salt solution

Question 12

what are the very reactive metals and how to extract them?

Answer 12

potassium, sodium, calcium, magnesium
very reactive metals can be extracted from their compounds by electrolysis (decomposition by electricity)

Question 13

what are the less reactive metals and how to extract them?

Answer 13

zinc, iron, lead, copper, silver
less reactive metals can be extracted from their compounds by reduction with carbon and heat

Question 14

what are the unreactive metals and how to extract them?

Answer 14

gold and platinum
unreactive metals such as gold and platinum are usually found combined

Question 15

the more reactive a metal is?

Answer 15

the more reactive a metal is, the harder it is to extract the metal from its compound. this is because reactive metals usually form stable compounds with strong bonds

Question 16

how does a blast furnace work?

Answer 16

1) raw materials are added to the top of the blast furnace (haematite, coke, limestone)
2)slag floasts on top of the iron
3) blast furnace is lined with a refractory material (aluminium oxide or magnesium oxide=high melting point)

Question 17

what happens when extracting iron in the blast furnace?

Answer 17

-coke burns in the blast of hot air to produce co2 and a large amount of heat
-co2 reacts with more coke to form CO
-CO reduces iron(III) oxide to molten iron

Question 18

what happens when removing impurities in the blast furnace?

Answer 18

thermal decomposition of limestone produces co2 and calcium oxide
the calcium oxide formed reacts with the silicon oxide and other impurities to form molten slag

Question 19

how does corrosion occur?

Answer 19

corrosion occurs when metals react with air and water

Question 20

what is the name for corrosion of iron and steel?

Answer 20

rusting

Question 21

what speeds rusting?

Answer 21

sodium chloride

Question 22

how can rusting be prevented?

Answer 22

rusting can be prevented by coating the metal with a protective layer (oil, paint, plastic). this prevents water and oxygen from reacting with the iron. however, if the layer is scratched or broken, rusting will occur

Question 23

what kind of resources are metals?

Answer 23

they are finite sources

Question 24

what are the advantages of recycling?

Answer 24

-they conserve and slow down the depletion of natural sources
do this by conserving finite metal ores and limited fossil fuels reserves(extraction requires high energy and burning of fossil fuels, which is also a finite source)
-economically
saves the cost of extracting new metals from ores
reduce cost as lesser landfill sites need to be built
-environmentally
lesser environmental problems and pollution as compared to extraction

Question 25

what are the disadvantages to recycling?

Answer 25

-economic costs
may incur more cost overall due to the cost of transporting the scrap metals to the processing plant, sorting and cleaning the scrap metals
-social costs
require effort and time for communities and businesses to adopt recycling as a lifestyle
-environmental costs
recycling process still cause a certain amount of air pollution