Dr Robson's Chemistry Unit 1a cards

Question 1

Give the name and charge of each sub-atomic particle.

Answer 1

Proton +1

Neutron 0

Electron -1

Question 2

How can you tell the group number of an element just by looking at the atoms that make it up?

Answer 2

Count the number of electrons in the outer shell.

Question 3

Give the atomic number and mass number of this atom containing six electrons, 6 protons and 6 neutrons.

Answer 3

Atomic number = 6 (number of protons)

Mass number = 12 (protons and neutrons - all particles in the nucleus)

Question 4

Why do all atoms have no overall charge?

Answer 4

Atoms have equal numbers of protons (+1 charge) and electrons (-1 charge).

Question 5

Name the two main catergories of elements in the periodic table.

Answer 5

Metals (about 75%) and Non-metals (about 25%).

Question 6

Name the group of elements in the centre of the periodic table, which includes gold, iron and copper.

Answer 6

The Transition elements.

Question 7

The electrolysis of aluminium oxide involves passing electricity through molten aluminium oxide. Why do the aluminium ions move towards the negative electrode?

Answer 7

Aluminium ions are positively charged.

Opposite charges attract.

Question 8

Give 3 reasons why you should recycle an aluminium can.

Answer 8

It requires less energy to recycle a can than to extract more aluminium from the Earth’s crust (more energy = more carbon dioxide released into the atomsphere = adding to climate change)

Aluminium is a non-renewable resource. Recyclnig conserves resources.

Less waste going into landfill, which is limited space.

Less aluminium quarries needed - less scars on the landscape.

Question 9

Give 3 disadvantages of a quarry near a town or village.

Answer 9

Noise pollution with explosions from quarry, extra traffic on roads transporting limestone.

Air pollution from extra traffic on roads and dust from quarry.

Visual pollution from quarry - an eyesore

Question 10

Give 3 advantages of a linestone quarry near a village/town.

Answer 10

Employment for local people.

Improve the local economy (more custom for local businesses)

Limestone is needed for building houses, bridges etc.

Imporved transport links with new/better/wider roads built by the quarry owners to help transport raw materials.

Question 11

Fe₂O₃ + …..CO –> …..Fe + …….CO₂

Balance this equation

Answer 11

Add a 3 before CO

Add a 2 before Fe.

Add a 3 before CO₂

Question 12

When iron oxide is reacted with carbon monoxide, the oxygen from iron oxide is removed to leave iron on its own. What is this reaction called?

Answer 12

A reduction reaction.

Question 13

Cast iron is brittle - it contains 4% carbon. To make the iron more flexible, the amount of carbon is reduced. This is done by bubbling oxygen into the liquid cast iron. What does the oxygen do?

Answer 13

The oxygen reacts with carbon to from carbon dioxide, which leaves the liquid iron as a gas.

Question 14

Give two advantges of adding small amounts of other metals to iron, making an alloy.

Answer 14

Alloys are harder than pure metyals, so increasing strength.

Alloys can corrode less than pure metals.

Question 15

What is an alloy?

Answer 15

A mixture of metal with other elements (another metal or non-metal)

Question 16

Name the waste gas formed when copper sulfide is heated with oxygen and describe why it is harmful to the environment.

Answer 16

Sulfur dioxide.

Gas dissolves in rain water to from acid rain. This reacts with metals/statues/buildings and lowers the pH of lakes or soil.

Question 17

Limestone can be changed to calcium oxide and carbon dioxide using a Bunsen burner.

Name the type of reaction occuring here.

Answer 17

Thermal decomposition

Question 18

Copper sulfate + iron –> ……………….. + ……………………

Complete the word equation by adding the names of the 2 products formed.

Answer 18

copper

iron sulfate

(iron is more reactive than copper, so displaces copper from its sulfate)

Question 19

Suggest 2 reasons why copper should not be disposed of in landfill.

Answer 19

Landfill space is limited. It will run out.

Extracting copper is expensive and requires lots of energy = lots of carbon dioxide released = adding to climate change.

Copper is non-renewable, why should recycle to conserve resources.

Question 20

……..CuO + C –> …………………………… + CO₂

Complete and balance the equation.

Answer 20

2 before CuO

2Cu in second gap.

Question 21

What is phytomining?

Answer 21

Extracting metals from the ground using plants.

Question 22

What is bioleaching?

Answer 22

Extracting metals from ores using bacteria.

Question 23

Whay are we now extracting copper from low grade ores (ores that contain only small amounts of copper)?

Answer 23

Copper is getting more and more scare (there’s not as much of it as there was).

There are less ores containnig lots of copper around.

Copper is getting more and more expensive.

Question 24

Why isn’t carbon used to extract aluminium from aluminium oxide like it is used ton extract iron?

Answer 24

Aluminium is more reactive than carbon (higher in the reactivity series). (Iron is lower than carbon)