My C1

Question 1

what is the overall charge on a atom?

Answer 1

neutral (zero)

Question 2

what is the charge of a proton?

Answer 2

1

Question 3

what is the charge of a neutron?

Answer 3

0

Question 4

what is the charge of an electron?

Answer 4

-1

Question 5

what is the central part of an atom called?

Answer 5

nucleus

Question 6

what particles do you find in the nucleus of an atom?

Answer 6

protons and neutrons

Question 7

what is the relative size of a proton?

Answer 7

1

Question 8

what is the relative size of a neutron?

Answer 8

1

Question 9

what is the relative size of an electron?

Answer 9

very small (negligable)

Question 10

what does the atomic number tell you in the periodic table?

Answer 10

how many protons it has (and also how many electrons)

Question 11

what does the mass number tell you in the periodic table?

Answer 11

how many protons + neutrons are in the nucleus

Question 12

how many electrons can the first three shells hold?

Answer 12

2, 8, 8

Question 13

if an atom gains one electron, what will it’s charge be now?

Answer 13

-1

Question 14

if an atom loses one electron, what will it’s charge be now?

Answer 14

. + 1

Question 15

what is the chemical formula for ‘calcium carbonate’?

Answer 15

CaCO3

Question 16

what is the main chemical found in limestone?

Answer 16

calcium carbonate

Question 17

what is made when calcium carbonate is heated?

Answer 17

calcium oxide and carbon dioxide

Question 18

what is thermal decomposition?

Answer 18

breaking down a chemical using heat

Question 19

what is the word equation for the thermal decomposition of calcium carbonate?

Answer 19

calcium carbonate –> calcium oxide + carbon dioxide

Question 20

what is the symbol equation for breaking down calcium carbonate using heat (thermal decomposition)?

Answer 20

CaCO3 –> CaO + CO2

Question 21

calcium oxide + water = ?

Answer 21

calcium hydroxide

Question 22

what is calcium hydroxide used for?

Answer 22

neutralisation. It is an alkali (farmers might use it on their fields to neutralise soil)

Question 23

calcium hydroxide + more water = ?

Answer 23

calcium hydroxide solution (LIMEWATER!)

Question 24

What happens to limewater when you add carbon dioxide?

Answer 24

goes cloudy

Question 25

how do we test for carbon dioxide?

Answer 25

add it to limewater and see if it turns cloudy

Question 26

What is cement made from?

Answer 26

Limestone and clay heated up

Question 27

what is concrete made from?

Answer 27

cement, sand and aggregate (rocks/stones)

Question 28

what is mortar made from?

Answer 28

cement and sand

Question 29

put these metals in order of reactivity (most reactive first) - copper, gold, potassium, aluminium.

Answer 29

potassium, aluminium, copper, gold

Question 30

why does gold stay shiny for a longer time than copper?

Answer 30

gold is less reactive

Question 31

what is phytomining?

Answer 31

phytomining uses plants to absorb metal compounds and that the plants are burned to produce ash that contains the metal compounds

Question 32

what is bioleaching?

Answer 32

bioleaching uses bacteria to produce leachate solutions that contain metal compounds.

Question 33

how are unreactive metals removed from the earth?

Answer 33

Unreactive metals such as gold are found in the Earth as the metal itself but most metals are found as compounds that require chemical reactions to extract the metal.

Question 34

how is carbon used to remove metals from their ores?

Answer 34

Metals that are less reactive than carbon can be extracted from their oxides by reduction with carbon, for example iron oxide is reduced in the blast furnace to make iron.

Question 35

how are metals more reactive than carbon mostly removed from their ores?

Answer 35

Metals that are more reactive than carbon, such as aluminium, are extracted by electrolysis of molten compounds. The use of large amounts of energy in the extraction of these metals makes them expensive.

Question 36

why is it expensive to remove aluminium and titanium from their ores?

Answer 36

there are many stages in the processes and large amounts of energy are needed.

Question 37

why is recycling metals a good idea?

Answer 37

We should recycle metals because extracting them uses limited resources and is expensive in terms of energy and effects on the environment.

Question 38

what is steel?

Answer 38

Steels are alloys since they are mixtures of iron with carbon. Some steels contain other metals.?

Question 39

what is an alloy?

Answer 39

a mixture of metals

Question 40

Describe some examples of different steels and their properties

Answer 40

?Low-carbon steels are easily shaped, high-carbon steels are hard, and stainless steels are resistant to corrosion.

Question 41

why are gold, copper and aluminium often made into alloys?

Answer 41

Pure copper, gold, iron and aluminium are too soft for many uses and so are mixed with small amounts of similar metals to make them harder for everyday use.

Question 42

what is copper useful for?

Answer 42

Copper has properties that make it useful for electrical wiring and plumbing. is a good conductor of electricity and heat can be bent but is hard enough to be used to make pipes or tanks does not react with water.

Question 43

why are aluminium and titanium very useful?

Answer 43

Low density and resistance to corrosion make aluminium and titanium useful metals.