Topic 2 - Materials From The Earth

Question 1

What is the formation if a Sedimentary Rock?

Answer 1

1. Rocks broken down by erosion
2. Layers of sediment build up on the sea bed
3. Over millions of years layers get burried under pressure and weight and are compressed to form sedimentary rocks
4. These can trap fossil fuels & are easily eroded

Question 2

Examples of sedimentary rocks ?

Answer 2

1. Chalk
2. Limestone

Question 3

What is the formation of Metamorphic rocks ?

Answer 3

1. They are formed due to heat and pressure on sedimentary rock over a long period of time
2. The mineral structure and texture changes
3. Very high temperatures break down the sedimentary rock and it reforms as small crystals

Question 4

Examples of a Metamorphic Rock?

Answer 4

1. Marble - formed from limestone and chalk. Much harder rock and has more even texture

Question 5

What is the formation of an Igneous rock?

Answer 5

1. Formed when the molten magma pushes up into the crust before cooling and solidifying
2. They contain various minerals randomly arranged and interlocking crystals

Question 6

What are the two types of an Igneous Rock?

Answer 6

1. Extrusive - Rocks cool quickly above ground making small crystals e.g. Basalt
2. Intrusive - cool slowly underground and make big crystals e.g. Granite

Question 7

What are the Cons of quarrying Limestone?

Answer 7

• Huge holes permanently changes the area
• Noise and dust pollution
• Destroys habitats
• Large lorries coming through villages causing more pollution
• Waste materials = ugly tips

Question 8

What are the Pros of quarrying Limestone?

Answer 8

• Provides materials needed for people
• Neutralises lakes and soils that are acidic
• There is usually restoration to the area
• Local improvements
• Create dyes, paints and materials
• Provides employment

Question 9

Why is Limestone a good building material?

Answer 9

• It is very insoluble although acid rain reacts with limestone and dissolves it away
• Old buildings are made out of it like cathedrals and the Houses of Parliament
• Can be made into cement and concrete and glass

Question 10

What is limestone chemical name and formula ?

Answer 10

• Calcium carbonate
• CaCO₃

Question 11

What is the thermal decomposition symbol and word equation for calcium carbonate?

Answer 11

• calcium carbonate > calcium oxide + carbon dioxide
• CaCO₃ > CaO + CO₂

Question 12

When all carbonates are thermally decomposed what do they give off?

Answer 12

• CO₂ (Carbon dioxide)

Question 13

What are the equations fro copper carbonate when it thermally decomposes?

Answer 13

• CuCO₃ > CuO + CO₂
• Copper carbonate > Copperoxide + Carbon dioxide

Question 14

What are the equations for zinc carbonate when it thermally decomposes?

Answer 14

• Zinc carbonate > Zinc oxide + Carbon dioxide
• ZnCO₃ > ZnO + CO₂

Question 15

What is rpoduced when calcium oxide reacts with water?

Answer 15

• Calcium hydroxide is produced

Question 16

What is the symbol for calcium hydroxide?

Answer 16

• Ca(OH)₂

Question 17

What is the test for CO₂ ?

Answer 17

• Bubble gas through limewater
• It will go cloudy due to calcium carbonate being formed

Question 18

In a chemical reaction what happens to the atoms?

Answer 18

• No atoms are lost or made
• mass reactants = mass products

Question 19

What is the balanced symbol equation for Magnesium + Oxygen = Magnesium oxide ?

Answer 19

Mg + O₂ = MgO

^ 2 of oxygen so you need 2 magnesium

2Mg + O₂ = 2MgO

Question 20

What are the 4 different state symbols ?

Answer 20

1. (s) Solid
2. (l) Liquid
3. (g) gas
4. (aq) Aqueous - dissolved in water