MOD 3 Chap 3.1 The Periodic table

Question 1

what groups make up the S block

Answer 1

groups 1-2

Question 2

what groups make up the P block

Answer 2

groups 13-18

Question 3

what groups make up the D block

Answer 3

3 to 12 (transition metals)

Question 4

what can be found in the F block

Answer 4

lanthanides

Question 5

define periodicity

Answer 5

the term used to describe the repeating patterns seen within groups and periods

Question 6

define nuclear pull

Answer 6

the attraction between the nucleus and the outer shell electrons

Question 7

define electron sheilding

Answer 7

the repulsion of outer shell electrons by the inner shell electrons

Question 8

How did John Dalton organise the periodic table

Answer 8

he put elements in order of atomic weight (did consider isotopes)

Question 9

How did John Newlands organise the periodic table

Answer 9

put elements in order of atomic mass (considered isotopes).

He grouped every 8 elements together

He did not leave gaps for undiscovered elements

elements in the same group were therefore not similar

Question 10

How did Dimitri Mendeleev

Answer 10

put elements in order of atomic mass

grouped elements together if they had similar chemical properties

left gaps for elements that had not been discovered yet

Question 11

define ionisation energy

Answer 11

a measure of the amount of energy needed to remove electrons from atoms

Question 12

define first ionisation energy

Answer 12

the energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous positive ions

-gaseous because in solids it is difficult to reach electrons

Question 13

explain what happens going down the group in terms of electron shielding

Answer 13

going down the group the number of protons increases so the nuclear pull increases but the number of shells also increases so the amount of electron sheiling increases.
the outer electrons are repulsed increasing the atomic radius

Question 14

going across a period the number shells stays the same so the ________ stays constant and the _____________ increases

Answer 14

going across a period the number shells stays the same so the electron shielding stays constant and the nuclear pull increases

Question 15

describe the factors affecting ionisation energy

Answer 15

atomic radius- larger atomic radius means a smaller nuclear attraction making it easier to loose electrons

Nuclear charge- the larger the nuclear charge the larger the attractive force on outer electrons

Electron shielding-the more inner shells the larger the shielding effect and smaller the nuclear attraction meaning it is more difficult to loose vallance electrons meaning a higher ionisation energy

Question 16

what happens to the atomic radius across a period

Answer 16

there is a decrease in atomic radius because there is an increased nuclear charge that pulls the electrons in towards it

Question 17

why is each ionisation energy higher than the successive one successive ionisation higher than the one before

Answer 17

as each electron is removed there is less repulsion between the remaining electrons and each shell is drawn closer to the nucleus. the positive charge will outweigh the negative charge meaning more energy is needed to remove outer shell electrons

Question 18

what factors does nuclear attraction experienced by the electrons depend on

Answer 18

atomic radius
nuclear charge
electron shielding

Question 19

a larger atomic radius means a _______ nuclear attraction

Answer 19

a larger atomic radius means a smaller nuclear attraction

Question 20

describe how toms in metallic bonding are organised

Answer 20

positive ions occupy fixed positions in the lattice while the outer shell electrons are delocalised.

Question 21

Properties of giant metallic lattices

Answer 21

high melting and boiling points because the attraction between positive ions and the negative delocalised electrons is very high meaning a high temperature is required to overcome the metallic bonds and dislodge the ions from their rigid positions in the lattice

good electrical conductivity- delocalised electrons move freely.

Question 22

define ductile and malleable

Answer 22

ductile- can be drawn out or stretched
malleable- can be hammered into different shapes

Question 23

as you go down group 2 reactivity _______

Answer 23

as you go down group 2 reactivity increases

Question 24

state the physical properties of group 2 elements

Answer 24

high melting and boiling points
light metals with low densities
form colourless (white compounds)

Question 25

group 2 elements are oxidised in their reactions to form 2+ ions meaning that they are ________ agents

Answer 25

group 2 elements are oxidised in their reactions to form 2+ ions meaning that they are reducing agents

Question 26

Going down group 2 solubility ________

Answer 26

Going down group 2 solubility increases along with alkalinity as more OH ions are released.

Question 27

uses of group 2 hydroxides

Answer 27

Ca(OH)2 is used I agriculture to neutralise acidic soils Mg(OH)2 and CaCO3 are used as antacids in treating indigestion

Question 28

as you go down the group the reactivity of halogens _______

Answer 28

as you go down the group the reactivity of halogens decreases because the atomic radius increases therefore electron shielding also increases meaning that the ability to gain an electron in the p sub shell and form -1 ions decreases.

Question 29

Cl2 colour in water and cyclohexane

Answer 29

water-pale green cyclohexane-pale green

Question 30

Br2 colour in water and cyclohexane

Answer 30

water-orange cyclohexane-orange

Question 31

I2 colour in water and cyclohexane

Answer 31

water-brown cyclohexane-violet

Question 32

define what is meant by a disproportionation reaction

Answer 32

a reaction in which the same element is both reduced and oxidised.

Question 33

method and positive test for carbonate ions

Answer 33

add dilute strong acid to the suspected carbonate, collect gas and pass it through lime water. the colourless gas produced turns lime water cloudy

Question 34

method and positive test for sulfate ions

Answer 34

SO4 2- ->> =add dilute HCl and barium chloride to the suspected sulfate, white precipitated of sulfate is formed.

Question 35

method of testing for halide ions

Answer 35

dissolve suspected halide in water. add aqueous solution of silver nitrate. if the colour change is hard to distinguish , add aqueous ammonia and note the solubility of the precipitate in aqueous ammonia

Question 36

positive test for silver chloride

Answer 36

white precipitate soluble in dilute NH3

Question 37

positive test for silver bromide

Answer 37

cream precipitate soluble in concentrated NH3 only

Question 38

positive test for silver iodide

Answer 38

yellow precipitate insoluble in both dilute and concentrated NH3

Question 39

method and positive test for ammonium cations

Answer 39

add sodium hydroxide solution to suspected ammonium compound and warm gently test any gas formed with red litmus paper ammonia gas will turn red litmus paper blue

Question 40

3 marker why does the metal groups melting points decrease going down the group

Answer 40

Melting points decrease because there are the same number of delocalised electrons per atom but the cations get heavier and larger. Therefore the cations are held in place less strongly by the attraction of the fixed number of delocalised electrons. Therefore less energy is required to overcome the attractive forces and cause melting

Question 41

Why do melting points increase cross periods

Answer 41

Across periods melting points increase because the number of delocalised electrons per atom increases ad the cation charge increases. Therefore the cations are held in place with greater forces of attraction. Therefore more energy is required to overcome the forces of attraction and melting occurs.

Question 42

explain what happens to electronegativity as you go down group 7

Answer 42

electronegativity decreases as you go down group 7 because bigger atoms more shielding weaker attraction between nucleus and 2 electrons in outer shell

Question 43

explain what happens to the boiling point going down group 7

Answer 43

boiling point increases because: more electrons stronger London forces more energy required to overcome London forces

Question 44

explain why oxygen has a lower first ionisation energy than nitrogen

Answer 44

in oxygen 2 electrons occupy the same orbital meaning there is more repulsion making it easier to remove electrons

Question 45

2nd ionisation energy for magnesium

Answer 45

Mg+(g)----->Mg2+(g) + e-

Question 46

what happens to successive ionisation energies

Answer 46

if one electron is removed there is less repulsion so each shell is drawn closer to the nucleus decreasing atomic radius , so the nuclear attraction increases and more energy is needed to remove successive electrons

Question 47

Chlorine and water reaction

Answer 47

Cl2(aq)+H2O(l)---> HClO(aq)+HCl(aq)

Question 48

Chlorine reaction that makes bleach

Answer 48

Cl2 (aq)+2NaOH (aq) ---> NaClO (aq)+NaCl (aq)+H2O (l)

Question 49

risks of using chlorine in drinking water

Answer 49

chlorine can react with hydrocarbons such as methane produced by decaying vegetation such as leaves , this forms chlorinated hydrocarbons which are suspected of causing cancer

Question 50

sequence of qualitative tests

Answer 50

1.Carbonate 2. Sulfate 3.Halides

Question 51

what groups have giant metallic structures

Answer 51

group 1 -14

Question 52

what groups have simple molecular structures

Answer 52

groups 15-18

Question 53

what groups have giant covalent structures

Answer 53

Carbon and silicon

Question 54

describe giant metallic structures and their boiling point//electrical conductivity

Answer 54

strong forces of attraction between positive ions/cations and negative delocalised electrons Electrical Conductivity=good in both liquid and solid Boiling Point=High

Question 55

describe giant covalent structures and their boiling point//electrical conductivity

Answer 55

strong forces of attraction between atoms. electrical conductivity=poor boiling point=high

Question 56

describe simple molecules structures and their boiling point//electrical conductivity

Answer 56

weak intermolecular forces BETWEEN molecules. covalent bonding WITHIN molecules non conductors low boiling points

Question 57

group 2 metal- what is oxidised and reduced

Answer 57

metal oxidised hydrogen reduced

Question 58

equation for chlorine oxidising Bromine

Answer 58

Cl2(aq) +2IBr- (aq) ----> 2Cl- (aq)+ Br2(aq)

Question 59

what ions can bromine oxidise

Answer 59

I- ions