Elements and the limestone cycle Flashcards Preview

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Flashcards in Elements and the limestone cycle Deck (32)
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1
Q

Describe 3 points about an atom’s nucleus. ..

A

It’s in the middle if the atom
It contains protons and neutrons Protons are positively charged and neutrons have no charge
The nucleus is positively charged overall
It’s tiny compared to the size of the atom

2
Q

Describe the electrons in 4 points …

A
They move around the nucleus 
they're negatively charged 
they're tiny but cover a lot of space 
they occupy shells around the nucleus 
The shells explain  the whole of chemistry
3
Q

Number of protons = the. …

The charge is always. …

A

Number of electrons Equal and opposite to the electrons

4
Q

If electrons are added or taken away what is the atom called?

A

An ion

5
Q

What decides what type of atom it is?

A

The number of protons

6
Q

If a substance contains onettle of atom it’s called an …

A

Element

7
Q

How are elements grouped?

A

Ones with similar properties are in the same groups

8
Q

What are the vertical columns called?

Why do the elements have similar properties?

A

Groups

They have the same number of electrons in their outer shell

9
Q

What is the top number next to the element symbol?

A

The mass number

Atomic number - proton number

10
Q

Electrons are always on…
Atoms are stable when they have…
If they are unstable they have… so they are….

A

shells
full electron shells
under 8 electrons on their outer shell (or 1, hydrogen)
they are reactive

11
Q

number of protons =

A

number of electrons

12
Q

What is the electronic structure for Nitrogen?

It has to inside ring electrons, then 5 on the outside.

A

2,5

13
Q

What bond does a compound have if there is a metal in it? What are the atoms like?
And if there’s no metal atom?

A

Ionic, ions

Covalent

14
Q

What compound is limestone mostly made up of?

A

CaCO3 - calcium carbonate

15
Q

What is thermal decomposition?

A

When a substance chemically changes into at least two different products when heated.

16
Q

What does calcium carbonate thermal decompose into?

A

calcium oxide and carbon dioxide

17
Q

Why can’t you thermally decompose group 1 metal carbonates in the class room?

A

The bunsen burner doesn’t reach high enough temps.

18
Q

What does calcium carbonate + sulphuric acid make?

A

Calcium sulphate salt, CO2 and water.

19
Q

What does calcium oxide (quick lime) + water =?

A

Calcium hydroxide - slaked lime

20
Q

What is calcium hydroxide (slaked lime) used for? (2)

A

Neutralising acidic soil in fields - it works faster than powdered limestone.
To test for CO2, if made into a solution, lime water, bubble the gas through it and the solution will turn cloudy if CO2 is present.

21
Q

Calcium hydroxide + CO2=

A

Calcium carbonate and H2O

22
Q

How is cement made?

A

Powdered limestone is heated in a kiln with powdered clay to make it.

23
Q

How is mortar made?

A

Cement can be mixed with sand and water to stick bricks together, you can also add calcium hydroxide to cement to make it.

24
Q

How is concrete made?

A

Mix cement with sand and aggregate

25
Q

What are the 5 negative effects of quarrying limestone?

A

It makes an ugly hole permanently scaring the landscape
Blasting the rocks with explosives creates a lot of dust and noise pollution is normal tranquil environments
It destroys the habitats of animals and birds
The limestone needs to be transported away in lorries cause noise and pollution
Waste material forms unsightly tips

26
Q

How does making things from limestone cause pollution?

A

Cement factories make a lot of dust which can cause breathing problems
Energy is needed to produce cement and to decompose CaCO3, from burning fossil fuels causing pollution

27
Q

What are the four good effects from quarrying limestone?

A

Stone used for houses and roads, and chemicals used in paints and dyes and medicines come from limestone
Products used to neutralise acidic soil, and lakes from acid rain
Used in power station chimneys neutralise sulphur dioxide causing acid rain
The quarry and associated businesses creates jobs and boosts the local economy leading to local improvements in infrastructure
Landscape and restoration takes place after the quarrying as part of the applied for planning permission

28
Q

What are limestone and concrete used for?

A

Building materials

29
Q

Why is limestone used for building? (4)

A

It’s widely available
Cheaper than granite or marble
Easy rock to cut
Some is more hard wearing than marble but still looks attractive

30
Q

What is concrete used for? (2)

But it’s….

A

Pouring into moulds to make blocks or panels that can be joined together.
It’s a quick and cheap way to make buildings
Unattractive

31
Q

Why is limestone and concrete used instead of wood? (3)

A

It doesn’t rot, it can’t be gnawed by insects or rodents and it’s fire resistant.

32
Q

Why is concrete used instead of metals?
But…
It’s stronger when…

A

It doesn’t corrode
it can crack
reinforced by steel bars