Chemistry Earth

Question 1

Name the 4 layers of the Earth.

Answer 1

Crust
Mantle
Outer core
Inner core

Question 2

State what a Mineral is.

Answer 2

Minerals are rock mixtures of naturally-occurring elements or compounds.

Question 3

List the six most common elements in the Earth’s crust.

Answer 3

Oxygen- 46.4%
Silicon-28.2%
Aluminium-8.3%
Iron-5.6%
Calcium-4.2%
Sodium-2,4%

Question 4

Name the three groups of rock and give an example for each.

Answer 4

Sedimentary rocks- Limestone
Igneous rocks- Granite
Metamorphic rocks- Marble

Question 5

Describe 4 properties of Sedimentary rocks.

Answer 5

-Sedimentary rocks are made up of separate grains so they may be soft and crumbly

-They do not normally contain crystals but may have fossils trapped within them

-Sedimentary rocks are usually porous. They have gaps between their grains. Air or water can get into these gaps.

-Most Sedimentary rocks are soft. You can scratch them easily.

Question 6

List the five stages in making a sedimentary rock.

Answer 6

Weathering
Erosion
Deposition
Compaction
Cementation

Question 7

Define ‘Weathering’.

Answer 7

Weathering- Breaks up all types of rock into pieces called sediments. Weathering makes Sediments but does not move them away.

Question 8

Define ‘Erosion and Transport’.

Answer 8

Weathered rock (sediments) move away from their rock. Together, the breaking of rock into sediments and their movement away is called erosion. Transport processes move sediments far from the original rock.

Question 9

Define ‘Deposition’.

Answer 9

Eventually, sediments will stop moving. They settle in one place. This is Deposition. Layers of different types of sediment may settle on top of each other.

Question 10

Define ‘Compaction and Cementation’.

Answer 10

Sand or other Sediment grains seperate.

After compaction, grains crush and interlock together.

After Cementation, mineral crystals cemented grains together.

Question 11

When does Igneous rock form?

Answer 11

When liquid rocks cools and freezes.

Question 12

State 3 properties of Igneous rocks.

Answer 12

Igneous rocks are hard.

They are durable- this means they are hard to damage.

They do not have gaps between the crystals. This explains why they are not porous.

Question 13

What is Intrusive rock?

Answer 13

Underground, liquid rock is called magma. Granite forms from magma. Underground, magma cools and freezes slowly and forms large crystals called intrusive rock.

Question 14

What is extrusive rock?

Answer 14

Basalt forms when liquid rock cools and freezes quickly. This happens under the sea, or when volcanoes erupt. On the surface liquid rock is called lava. Lava forms small crystals called extrusive rock.

Question 15

How is Marble formed?

Answer 15

Marble starts out as limestone. Marble forms when limestone below the earth’s surface heats up. The limestone do not melt, the particles are rearranged.

Question 16

How is Slate formed?

Answer 16

Slate starts out as Mudstone. Slate forms when high pressure underground squashes the mudstone. This squeezes out the water and forms new crystals.

Question 17

What is the rock cycle?

Answer 17

Different rock types, and the processes that change one rock type into another.

The rock cycle shows how rocks change, and how materials are recycled over millions of years.

Question 18

What is Uplift?

Answer 18

When Continents collide, huge forces inside the earth push rock upwards, and mountains can form. This is called Uplift.

Question 19

What is a Ceramic material?

Answer 19

Toilets are made from pottery. Pottery is an example of a ceramic material

Ceramic materials are compounds- they include metal silicates, metal oxides, metal carbides and metal nitrides.

Question 20

State 4 properties of Ceramics.

Answer 20

Hard– you can only scratch them with harder materials

Brittle- they break easily

Stiff- they are difficult to bend

Solid at room temperature, with high melting points

Strong when forces press on them

Easy to break when stretched

Electrical insulators

Unreactive with water, acids, or alkalis

Question 21

Uses of Ceramics.

Answer 21

Bricks are strong when forces press on them. They are also durable and attractive. This makes them suitable for buildings.

Ceramics don’t react with water, acids or alkalis, this makes them useful
for plates, bowls and mugs etc.

Ceramics have high melting points. This makes them suitable for jet-engine turbine blades which get very hot.

Ceramics don’t conduct electricity. They are not damaged by water. This makes them useful for electrical power-line insulators.

Question 22

Can you think of any uses for artificial satellites?

Answer 22

Earth observations (weather)
Communications
Scientific investigation
Military
Navigation

Question 23

What are Stars?

Answer 23

Stars are bodies that give out light and may have their own solar systems with planets, called exoplanets, orbit around them.

Question 24

What is our nearest Galaxy?

Answer 24

Our nearest large galaxy is Andromeda, which you can see with the naked eye

Question 25

What is a galaxy?

Answer 25

A galaxy is a collection of stars held together by gravity. At the centre is a large black hole.

Question 26

How fast does light travel?

Answer 26

The speed of light is about 300,000 km/s-
that’s 18,000,000 km every minute.

The Sun is about 150,000,000 km from the Earth.

Question 27

What is light measured in?

Answer 27

A light minute is the distance that light travels in 1 minute = 18,000,000 km (Venus is about 2 light minutes away from Earth)

A light hour is the distance that light travels in 1 hour = 1,080,000,000 km (Saturn is about 1.5 light hours away from Earth)

A light year is the distance that light travels in a year- which is over 9 million, million km.

Proxima Centauri our closest neighbouring star is about 4.244 light-years away from the Sun.

Question 28

How far away is the sun?

Answer 28

146 million kilometers.

Question 29

What is the hottest planet?

Answer 29

Venus.

Question 30

Which planet has the most volcanoes?

Answer 30

Venus.

Question 31

Name all of the planets people have walked on.

Answer 31

Earth.

Question 32

Why is there Day and Night?

Answer 32

There is day and night on Earth because Earth spins on its axis. It takes about 24 hours to complete one full rotation.

The Sun rises in the east, reaching its highest point at noon, then sets in the west. The Sun isn’t moving. You are.

Question 33

You see the Sun rise in the ____ and set in the____ because the Earth _____.

Answer 33

You see the Sun rise in the EAST and set in the WEST because the Earth SPINS.

Question 34

Why is it hotter in summer?

Answer 34

New information- The orbiting Earth

The Earth’s axis is tiled by 23.4o

It is hotter in the summer than the winter because the tilt of the Earth’s axis means that the Sun’s rays spread over a smaller area and the days are longer.

In the summer in the North Pole, the tilt of the axis means that the Sun doesn’t set. In the winter the Sun does not rise. This also happens at the South Pole.

Question 35

Why does the Moon look different and is there a pattern?

Answer 35

The Moon takes 27 days and 7 hours to orbit the Earth once (which is spinning once every 24 hours)