Elements of Life

Question 1

How did the structure of the atom develop over time?

Answer 1

First was plum pudding model

Disproved by Geiger marsden

Bohr model - protons, neutrons and electrons

Evidence for shells - ionisation enthalpies and spectra

Question 2

What reaction conditions are needed for fusion reaction?

Answer 2

High temperature and pressure

Question 3

How do covalent bonds work?

Answer 3

There is a balance between repulsive forces between the nuclei and there is attractive forces between the nuclei and electrons

Question 4

What is the bond angle of a tetrahedral molecule?

Answer 4

109.5

Question 5

What is the bond angle of a pyramidal molecule with a lone pair?

Answer 5

107

Question 6

What is the bond angle of a bent molecule with two lone pairs?

Answer 6

104.5

Question 7

How do giant ionic compounds work?

Answer 7

Overall attraction in a lattice made of attraction beteeen I one of different charge shd repulsion of ions of the same charge

Question 8

Explain the Trend in meltibg points in period 2 and 3

Answer 8

In period 2 meltibg point increases until carbon/silicon (increased delocalised electrons in metallics structure) then drops suddenly and decreases as molecules have less atoms so weaker intermolecular bonds

Question 9

Negative ions with -1 charge

Answer 9

Nitrate no3

Hydroxide

Hydrogencarbonate

Question 10

Ions with -2 charge

Answer 10

Sulphate

Carbonate

Question 11

Ions with + charge

Answer 11

Ammonium

Question 12

Ions with +2 charge

Answer 12

Copper

Zinc

Iron (ii)

Question 13

Ion with +3 charge

Answer 13

Iron 3

Question 14

What happens and what is the trend when group 2 metals react with water?

Answer 14

Form metal hydroxides and hydrgen

Increasing reactivity down group as outer electrons are more easily lost

Question 15

What hapens when group 2 metals react with oxygen?

Answer 15

For metal oxides

Question 16

What is the trend in thermal stability of group 2 carbonates?

Answer 16

Increased stability down group

The ions have lower charge density so less distortion

Question 17

What is the trend in solubility of group 2 hydroxides?

Answer 17

Increase in solubility down the group

Question 18

What is the trend in solubility of group 2 carbonates?

Answer 18

Decreases down group

Question 19

Define ionisation ebthalpy?

Answer 19

The entgalpy needed to remove the 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous ions

Question 20

What is the trend in ionisation enthalpues and why?

Answer 20

Increase across the period
And decreases down group

Atomic radius decreases

Nuclear charge Increases

Electron shielding

Question 21

Solubility of nitrates?

Answer 21

Soluble

Question 22

Sulfates are soluble except?

Answer 22

Barium

Calcium

Lead

Question 23

Solubility of carbonates?

Answer 23

Insoluble except lithium potassium sodium and ammonium

Question 24

Solubility of hydroxides?

Answer 24

Insoluble expect lithium sodium potassium strontium calcium barium and ammonium

Question 25

Test for calcium?

Answer 25

White precipitate with sodium hydroxide

Question 26

Test for copper?

Answer 26

Blue precipitate with sodium hydroxide

Question 27

Test for iron (ii)?

Answer 27

Green precipitate with sodium hydroxides

Question 28

Test for iron (iii)?

Answer 28

Brown precipitate with sodium hydroxide

Question 29

Test for aluminium?

Answer 29

White dissolvable precipitate with sodium hydroxide

Question 30

Test for carbonates?

Answer 30

HCl forms co2 so turns lime water cloudy

Question 31

Test for sulfates?

Answer 31

Barium chloride | Forms a white precipitate

Question 32

Test for ammonia

Answer 32

Litmus paper | Red- blue

Question 33

Test for halides?

Answer 33

Add silver nitrate White Cream Yellow

Question 34

What happens when you add group 2 oxides and hydroxides to water?

Answer 34

They form alkaline solutions | Oxides form stronger alkalines down the group

Question 35

Group 2 hydroxides/oxides and acids?

Answer 35

Neutralisation

Question 36

What is the order of the electromagnetic spectrum?

Answer 36

Infrared visible ultraviolet

Question 37

What is the melting point, solubility in water and conductivity like for giant ionic?

Answer 37

High melting point Most soluble except: ba, ca, pb ag sulphate Ag+ pb halides Carbonates Hydroxides (except g1 and nh4) Conduct when in solution of molten

Question 38

What is the melting point, solubility in water and conductivity of giant metallic structures?

Answer 38

High melting point Insoluble in water, some react Conductive when solid or liquid

Question 39

What is the melting point, solubility in water and conductivity I’d giant covalent ?

Answer 39

Very high melting point Insoluble Unconductive - except graphite

Question 40

What is the melting point, solubility in water and conductivity of simple covalent?

Answer 40

Low melting point Insoluble unless the have polar group Inconductive

Question 41

What is an acid?

Answer 41

Has the ability to transfer H+

Question 42

What is a base?

Answer 42

Has ability to accept H+ ions

Question 43

What is an alkali?

Answer 43

Base that dissolved in water to produce hydroxide ions

Question 44

What do solid and dashed wedges mean?

Answer 44

Solid wedges coming out of plane of paper, dashed are going behind

Question 45

Define activation energy

Answer 45

The minimum energy needed in a collision to cause a reaction

Question 46

What is meant by the term mole?

Answer 46

The amount of substance that has the same number of particles as there are atoms in 12g of carbon 12

Question 47

What is an salt?

Answer 47

A compound where a H+ in an acid has been replaced by a metal ion

Question 48

What is relative isotopic mass?

Answer 48

The mass of the atom compared to 1/12 th of the mass of carbon 12

Question 49

describe the appearance and origin of the emission spectrum of the sun and explain how the lines can be used to identify elements

Answer 49

``` Appearance and origin • atoms absorb energy • electrons move up energy levels • energy levels quantised • (electrons) drop back down • emit light • ∆E = hv • give coloured lines ``` How lines can be used • atoms of each element have their own specific energy levels • thus different gaps • thus different frequency lines • frequencies of lines can be checked against a database

Question 50

what is charge density?

Answer 50

the ratio of charge on an ion to its volume