Chemistry-C4

Question 0

H2 or H3 means they are what?

Answer 0

Molecules

Question 1

A what is + or - charged

Answer 1

Ion

Question 2

No charge means that they are

Answer 2

An atom

Question 3

What does an atom need to be stable?

Answer 3

A full shell

Question 4

Metals are positive, they what?

Answer 4

Loose electrons

Question 5

Non-metals are negative, they what?

Answer 5

Gain electrons

Question 6

Ionic bonding is between what?
Metals and metals
Non metals and non metals
Metals and non metals

Answer 6

Non metals and metals

Question 7

Ionic compound facts

Answer 7

Solid at room temp - form crystals
High melting and boiling points
Dissolve to for solutions that conduct electricity
Conduct electricity when molten

Question 8

Daltons theory

Answer 8

Atoms were tiny round balls
All the same
If the same elements they were attached via hooks

Question 9

Thompsons theory

Answer 9

Discovered electrons and their negative charge
Realised atoms weren’t the smallest thing
If atoms are neutral and electrons are negative there had to be something positive

Question 10

Rutherfords theory

Answer 10

Proved that atoms were not solid they were ‘empty space’

Question 11

Bohrs theory

Answer 11

Theory that atoms were on fixed orbits

Question 12

What is covalent bonding?

Answer 12

When atoms join together to share electrons - creates a strong bond

Question 13

If atoms share 1 electron what is the bond called?

Answer 13

Single

Question 14

If atoms share 2 electrons what is the bond called

Answer 14

Double

Question 15

If atoms share 3 electrons what is the bond called

Answer 15

Triple

Question 16

Properties of molecular solids

Answer 16

Brittle 
Don't conduct electricity 
Insoluable in water 
Soluable in petrol
Low melting and boiling points

Question 17

Properties of alkali metals (group 1)

Answer 17

Stored in oil because they will react with oxygen of moisture in the air
Less dense than water
Cut easily
Reactivity increases as you go down the group

Question 18

What is the equation for alkali metals and water?

Answer 18

Alkali metal + water -> metal hydroxide + hydrogen

Question 19

What is the symbol equation for alkali metals and water?

Answer 19

Metal (lithium - Li) + H2O -> LiOH + H2

Question 20

Describe what happens in flame tests

Answer 20

1. Heat up loop and burn any unwanted dust
2. Dip into hydrochloric acid
3. Dip into alkali compound solid
4. Hold in flame and identify ions

Question 21

In flame tests what colour is lithium?

Answer 21

Red

Question 22

In flame tests what colour is sodium

Answer 22

Orange/yellow

Question 23

In flame tests what colour is potassium

Answer 23

Lilac

Question 24

Why do alkali metals become more reactive as you go down the table?

Answer 24

They have more full shells which means the ones on the outside are further away from the nucleus which means it is easier for it to leave because the attraction isn't as strong as the ones closer to the nucleus

Question 25

what state are the halogens (group 7)

Answer 25

``` Fluorine - gas Chlorine -gas Bromine -liquid Iodine -solid Asinine ```

Question 26

What is thermal decomposition? And give an example

Answer 26

Breaking down a substance into 2 or more products using heat Copper carbonate -> copper oxide + carbon dioxide

Question 27

Thermal decomposition always makes what?

Answer 27

A oxide and carbon dioxide

Question 28

Give 3 sources of water

Answer 28

River Rocks Reservoirs 3R's

Question 29

What could water contain?

Answer 29

Nitrates (from fertilisers) Sewage Rubbish Lead compounds (from old pipes)

Question 30

What are the 3 methods of purifying water?

Answer 30

Filtration Sprayed onto layered sand to filter through Sedimentation Chemical added to make them clump together and be filtered Chlorination Chlorine gas injected into water to kill microbes