Nat 4 Chemistry Assessment

Question 1

What is the formula for metals reacting with oxygen

Answer 1

metal + oxygen -> metal oxide
eg. magnesium + oxygen -> magnesium oxide

Question 2

Metals reacting with oxygen can make physical reactions like?

Answer 2

slight glow, bright glow, bright flame

Question 3

What is the formula for metals reacting with acid?

Answer 3

metal + acid -> salt + hydrogen

Question 4

Sulfuric acid becomes?

Answer 4

Sulfate

Question 5

Hydrochloric acid becomes?

Answer 5

Chloride

Question 6

Nitric acid becomes?

Answer 6

Nitrate

Question 7

What is the formulae of metals reacting with water?

Answer 7

metal + water -> metal hydroxide + hydrogen

Question 8

metals are found in the earths crust in?

Answer 8

rocks

Question 9

what is an ore?

Answer 9

a rock that contains a naturally occuring metal compound

Question 10

what metals are found uncombined?

Answer 10

silver and gold

Question 11

Most reactive metals in order

Answer 11

potassium, sodium, lithium, calcium, magnesium, aluminium

Question 12

Middle reactive metal

Answer 12

carbon

Question 13

Least reactive in order

Answer 13

zinc, iron, copper, silver and gold

Question 14

what method do you use to extract potassium, sodium, lithium, calcium, magnesium and aluminium?

Answer 14

Extracted by electrolysis of molten compounds

Question 15

what method do you use to extract zinc, iron and copper

Answer 15

Extracted by reduction, by heating with carbon

Question 16

what do you use to extract silver and gold?

Answer 16

nothing as they are found as pure elements in nature

Question 17

when a metal is exposed to the environment it will react and change into its?

Answer 17

ions

Question 18

What is corrosion?

Answer 18

corrosion is a chemical reaction where the surface of a metal changes into a compound

Question 19

what is rusting?

Answer 19

rusting is the special name to the corrosion of iron

Question 20

what causes corrosion?

Answer 20

different metals will corrode at different rates due to their reactivity

Question 21

in order for corrosion to occur what must be present?

Answer 21

water and oxygen

Question 22

how do you detect rust?

Answer 22

Using ferroxyl indicator rust will be present when it changes from yellow to blue.

Question 23

2 ways to prevent rust?

Answer 23

physical barrier and sacrificial protection

Question 24

what types of physical barriers would you use?

Answer 24

paint, oils and grease or coating steel with a second protective metal

Question 25

what is sacrificial protection?

Answer 25

connecting a metal above iron in the electrochemical series which will slow down the corrosion of iron.

Question 26

chemical energy ->

Answer 26

electrical energy

Question 27

a simple battery is called a?

Answer 27

cell

Question 28

how can a cell be made?

Answer 28

by joining two different metals

Question 29

an electrical current will flow from the?

Answer 29

most reactive to the least reactive

Question 30

all our food comes from?

Answer 30

plants which is either directly or by eating animals that have eaten plants.

Question 31

plants need what for healthy growth?

Answer 31

Nutrients

Question 32

what are the three main elements present in fertilisers?

Answer 32

Nitrogen Phosphorus and Potassium N P K

Question 33

why is nitrogen added, what does it do?

Answer 33

for plant colour and growth

Question 34

why is phosphorus added, what does it do?

Answer 34

for fruit and flowers

Question 35

why is potassium added, what does it do?

Answer 35

for strong roots

Question 36

different plants need different nutrients in different?

Answer 36

proportions

Question 37

fertilisers MUST contain at least one of what?

Answer 37

the essential 3 elements

Question 38

fertilisers must also be?

Answer 38

soluble in water

Question 39

why must fertilisers be soluble in water?

Answer 39

so that they can be absorbed through the roots of the plants

Question 40

fertilisers must also be easily?

Answer 40

spread

Question 41

what is compost?

Answer 41

plant material that has rotted leaving nutrients behind

Question 42

what is manure?

Answer 42

waste from animals that are rich in nutrients

Question 43

what are some advantages of natural fertilisers?

Answer 43

environmentally friendly, slow release of nutrients and can improve soil structure.

Question 44

what are some disadvantages of natural fertilisers

Answer 44

expensive, take longer to work and an unpleasant odour

Question 45

what does synthetic mean?

Answer 45

man made - made by industrial chemists

Question 46

what are some advantages of synthetic fertilisers?

Answer 46

quick results and affordable

Question 47

what are some disadvantages of synthetic fertilisers?

Answer 47

pollution, soil degradation and reduces nutritional content of food

Question 48

what can plastics be used for?

Answer 48

garden furniture and clothing

Question 49

plastics are examples of?

Answer 49

polymers

Question 50

what are polymers?

Answer 50

long chain molecules made up of smaller units called monomers

Question 51

many monomer units are joined together in a process called?

Answer 51

polymerisation

Question 52

when the monomer propene undergoes polymerisation it becomes the polymer?

Answer 52

polypropene

Question 53

plastics are used based on their?

Answer 53

chemical properties

Question 54

plastics are very?

Answer 54

versatile

Question 55

what toxic gas do plastics release when burned?

Answer 55

carbon monoxide

Question 56

what other toxic gases can they release?

Answer 56

hydrogen chloride and hydrogen cyanide

Question 57

what happens when these gases are released?

Answer 57

they can cause health problems for both animals and humans after exposure for too long

Question 58

most plastics are?

Answer 58

non - biodegradable

Question 59

what does non - biodegradable mean?

Answer 59

it means that plastics do not break down in the soil?

Question 60

what type of natural material can be used for packaging of food products?

Answer 60

seaweed

Question 61

why is seaweed suitable?

Answer 61

its moisture and heat resistant meaning it can be put it a microwave oven.

Question 62

what are ceramics made from?

Answer 62

clay, sand and feldspar ( a rock that has metals present as compounds, but not as ores)

Question 63

the materials used to make ceramics materials are?

Answer 63

ground to a fine powder, mixed together and fired in a kiln at high temp (700-2000 degrees)

Question 64

ceramics are often?

Answer 64

hard and strong

Question 65

but they can also be?

Answer 65

brittle and can break easily

Question 66

advanced ceramics have been developed with what type of desirable properties?

Answer 66

hard wearing, resistant to high temps, good corrosion resistance and low conductivity of electricity and heat.

Question 67

where can ceramic be used?

Answer 67

it can be coated on to metals to make cookware, this makes a non - stick coating which is wear resistant.

Question 68

where can ceramic also be used?

Answer 68

in cars, catalytic converter to reduce pollution, the spark plugs in the engine, materials on the brake pads which give better wear and the clutch plate as part of the gear box.

Question 69

ceramic materials are?

Answer 69

lightwear, strong, hard - wearing and can withstand high temps.

Question 70

why are ceramic materials cheap to produce?

Answer 70

as the raw materials they are made from are available

Question 71

everything in the universe began when?

Answer 71

during a massive explosive event 13.7 billion years ago called the 'big bang'

Question 72

these hydrogen atoms join to form?

Answer 72

heavier nuclei, therefore more elements - nuclear fusion

Question 73

what is a supernova?

Answer 73

a supernova is the explosion of a star

Question 74

when large stars grow old and run out of fuel they?

Answer 74

expand and explode sending shock waves creating more fusion reactions.

Question 75

supernova explosions eject what?

Answer 75

all of the elements which have formed inside the star into the universe

Question 76

the nuclei of some atoms are?

Answer 76

radioactive, this is due to their nuclei being unstable

Question 77

in the nuclei of radioactive elements the ------- forces between the ------ charged protons are so large that the nucleus gives off ------ radiation to become -----

Answer 77

repulsive, positively, radiation, stable

Question 78

what is background radiation?

Answer 78

this natural level of radiation is called background radiation

Question 79

sources of background radiation

Answer 79

cosmic rays, animals, rocks, soil

Question 80

uses of background radiation in medicine

Answer 80

x - rays, treatment of cancers, medical scans