redox and periodicity

Question 1

define electronegativity

Answer 1

ability of an atom to attract a shred pair of electrons towards itself

Question 2

how does electronegativity change down a group

Answer 2

decreases
-atomic radius Increases
-less attraction between nucleus and shared pair of electrons

Question 3

how does electronegativity change across a period

Answer 3

increases
- atomic radius decreases
- greater attraction between nucleus and shared pair of electrons

Question 4

what is the oxidation states for all elements

Answer 4

0

Question 5

what is the oxidation state in simple ions

Answer 5

the same as the charge

Question 6

what is the oxidation stats in compounds

Answer 6

0

Question 7

what is the oxidation state in complex ions

Answer 7

charge on ion

Question 8

what are the 3 exceptions to oxidation rules

Answer 8

in peroxides O=2
H=1
O=2

Question 9

what do the roman numerals apply to for oxidation rules

Answer 9

appear after the element they apply to

Question 10

what are the 3 different definitions of oxidation

Answer 10

loss of e-
gain of oxygen
increase in oxidation state

Question 11

what are the 3 definitions of reduction

Answer 11

gain of e-
loss of oxygen
decrease in oxidation state

Question 12

how would you describe an increase in oxidation state

Answer 12

number gets more positive

Question 13

define disproportionation

Answer 13

the same element from teh same species is both oxidised and reduced

Question 14

how to draw ionic equations

Answer 14

look for aqueous elements and separate cations and anions
remove ions that havent changed
separate each side to give them their own half equation

Question 15

who discovered the modern periodic table

Answer 15

Mendeleev

Question 16

how is the periodic table organised

Answer 16

by chemical properties

Question 17

what is the historically changed part o the periodic table

Answer 17

used to be arranged by atomic weight, now arranged by atomic number

Question 18

define periodicity

Answer 18

repeating trends + patterns across the periodic table

Question 19

whatis the periodicity down the group

Answer 19

the more electron shells
atomic radius increases

Question 20

what is the periodicity across a period

Answer 20

atomic radius decreases
increased nuclear charge (more protons)
similar shielding
greater attraction between electrons + nucleus

Question 21

define ionisation

Answer 21

the removal of electrons

Question 22

define first ionisation energy

Answer 22

energy required to remove one electron from each atom in one mole of gaseous +1 ions

Question 23

why is ionisation always endothermic

Answer 23

an electron is lost is breaking bonds - generally endotremic

Question 24

what 3 factors affect ionisation energy

Answer 24

atomic radius
number of protons (nuclear charge)
electron shielding

Question 25

what is the trend in ionisation energy between group 7 and 8

Answer 25

large increase between shells electron being removed is closer to the nucleus greater attraction more energy required to remove electron (proof of electron shells)

Question 26

what is the trend in ionisation energies across a period

Answer 26

small increase same proteons attracting less electrons stronger attraction more energy needed

Question 27

what is the trend in ionisation energies between orbitals

Answer 27

small decrease repulsion between electrons in 2p orbitals easier to remove electrons

Question 28

what is the trend in ionisation energies down a group

Answer 28

decreases atomic radius decreases same nuclear charge weaker attraction between electron being removed and the nucleus

Question 29

what is nuclear charge

Answer 29

protons - electrons not on outside shell

Question 30

what could cause a trend in ionisation energies 4

Answer 30

atomic radius electron shielding nuclear charge repulsion between electrons in orbitals

Question 31

what is the evidence electron subshells exist

Answer 31

electron being removed from a 2p orbital which is further away from the nucleus therefore less attraction

Question 32

what are the 2 things that cause trends in melting points

Answer 32

affected by structure and bonding

Question 33

what structure has the highest melting point

Answer 33

giant covalent structure

Question 34

what structures' melting point increases as charge increases

Answer 34

giant metallic structure

Question 35

what structure's melting point decreases as number of electrons on outer shell decreases meaning stronger London forces

Answer 35

simple molecules

Question 36

what structure has the weakest melting point due to weak London forces

Answer 36

monoatomic