3.1

Question 1

principle quantum number

Answer 1

The principal quantum number (n) tells you the energy level or shell number where the electron is.

Question 2

Atomic radius definition + trend

Answer 2

Atomic radius is the distance from the nucleus of an atom to the outermost electron shell.

• Decreases across periods: Additional proton -> higher nuclear charge -> greater attraction between electrons and nucleus causing radius to become smaller
• Increases down groups -> Valence electrons are added to a higher energy level -> presence of additional shell shields the electrons from the attractive electrostatic froce of the nucleus ->** Low effective nuclear charge **

Question 3

Effective nuclear charge

Answer 3

Diminished electrostatic force experienced by a shielded valence electron - Zeff

Question 4

Ionic radius trend for cations + examples of groups

Answer 4

Cations have more protons than electrons, increasing the nuclear electrostatic force of attraction so ionic radius is smaller than atomic radius - Group 1,2 13

Question 5

Ionic radius trend for anions
and how can this increase further?

Answer 5

Anions: More electrons than protons so force of attraction between nucleus and the additional electrons is smaller so ionic radius is greater than atomic radius

the greater the magnitude of charge, the greater the atomic radius

Question 6

Ionic radius general

Answer 6

Increases down the group
Decreases across period

Question 7

Ionization energy def + equation

Answer 7

Minimum energy required to eject an electron out of a neutral atom or molecule in its ground state

x + IE = X (+1) + e-

Question 8

IE trend

Answer 8

Generally decreases down groups due to greater shielding effect, less energy required to **ionize atoms. **

Across a period increases as protons increase so outermost electrons held closer to the nucleus due to increased nuclear charge. **At the same time shielding effect remains nearly constant **

Question 9

Electron affinity definition + equation

Answer 9

Energy released when an additional electron is attached to a neutral atom or molecule

X + e- = X- + EA

Question 10

Electron affinity trend + PREDICTION

Answer 10

Trend for first electron affinity is like ionization energy,

nuclear charge increases across a period and so more energy is released when an electron is added

ONLY GROUP 1 ELEMENTS: Electron affinity decreases down the group due to shielding

Question 11

electron affinity decreasing down a group +examples

& why cant the data be accurate sometimes

Answer 11

Sometimes it drops cuz adding an electron might result in a less stable electron config (silicon and phosphorus)

+ not always accurate data (like for metals) cuz adding an electron is not favourable

Question 12

electronegativity definition

Answer 12

atoms ability to attract a pair of electrons from a chemical bond to itself

Question 13

electronegativity trend & why

Answer 13

decreases down groups and increases across periods

smaller atoms with nearly complete valence shells will attract electrons more easily than larger atoms with fewer valence electrons

Question 14

metallic character trend and why

Answer 14

linked to ionization energy
decreases across the period
increases down groups
high metallic character have delocalized electrons so usually have low ionization energies

Question 15

bronsted lowry acids and bases

Answer 15

acid: donates protons H+

base: accepts protons H+

Question 16

reaction of metal and water & how do they increase

Answer 16

X + H20 = 1/2H2 + XOH

more vigorous going down the grp cuz metallic character increases

Question 17

Lewis acids and bases

Answer 17

Lewis acids: accept electron pairs

Bases: Donate electron pair

Question 18

halide ions + halogens reactions occurs when

and increases when

Answer 18

occurs when more electronegative element can oxidize the lesser electronegative element

increases with greater difference in electronegativity between reacting species

F2 reacts faster with I than CL

Question 19

How do oxides change across periods

Answer 19

More acidic, less basic

Question 19

Metallic / non metallic oxides in terms of lewis and what do they do

Answer 19

metallic oxides: lewis bases, donate electron pair

MgO + H20 = Mg(OH)2

non metallic oxides: lewis acids, accept electron pair

CO2 + H2O = H2CO3

Question 19

Amphoteric def + example of equations

Answer 19

Behaves as both a lewis acid and base like Al203

AL203 + 2NaOH = 2Na(Al(OH)4) + 3H20

Al203 + 6HCL = 2ALCl3 + 3H20

Question 20

why is rainwater naturally acidic + equation

Answer 20

presence of dissolved carbon dioxide forms weak carbonic acid

C02 + H20 = H2C03

Question 21

reactions for n02 and how does nitrous acid become nitric acid

Answer 21

nitrogen dioxide + h20 = HN03 + HN02 (nitrous acid)

Nitrous acid oxidized by atmospheric oxygen

2HN02 + 02 = 2HN03

Question 21

Typical pH value for rain and when do we say its acid rain and why does it occur

Answer 21

typically 5.6

Its acid rain when below 5.6 which occurs due to nitrogen and sulfur dissolving in the air

Question 22

Sulfur Dioxide and Nitrogen dioxides come from?

Answer 22

* Naturally: volcanic eruptions and decomposing vegetation * Industrial processes: combustion of fossil fuels with high levels of sulfur impururities

Question 23

reactions for s02 and how does sulfurous acid become sulfuric acid

Answer 23

S02 + H20 = H2S03 Sulfurous acid is oxidized to form sulfuric acid 2H2S03 + 2H2S04

Question 24

Why & how is the ocean affected by carbonic acid

Answer 24

It absorbs a lot of c02 released into the air which forms carbonic acid. This affects the ability of coral reefs and shellfish to calcify their skeletons

Question 25

oxidation state represents

Answer 25

charge on atom in compound describes electrons shared or transferred when forming a bond

Question 26

Important rules for oxidation states

Answer 26

Oxidation state of fluorine is -1 in all compounds Oxidation of group 1/2 metals is always +1 / +2

Question 27

oxidation state of oxygen is always, except....

Answer 27

Oxidation state of oxygen is -2 except OF2 (since fluorine is more electronegative oxygen has +2) and in peroxides like h202 where it is -1

Question 28

oxidation state of hydrogen is

Answer 28

-1 when combined with metals (less electronegative) +1 when combined with more electronegative elements (non metals)

Question 29

Hydrogen in -1 oxidation state is called

Answer 29

hydride ion

Question 30

NAME N02- N03- S032- S042-

Answer 30

Nitrite (III) Nitrate (V) Sulfite (IV) Sulfate (VI)

Question 31

Discontinuity in ionization energy between berrylium and boron

Answer 31

Berrylium - 1s2 2s2 Boron - 1s2 2s2 2p1 Even though boron has greater charge its its outermost electron is in the 2p orbital, which is higher in energy and less stable than the 2s orbital of Be. easier to remove lone electron rather than paired electron

Question 32

Discontinuity in ionization energy between nitrogen and oxygen

Answer 32

Nitrogen - 1s2 2s2 2p3 Oxygen - 1s2 2s2 sp4 In nitrogen the 3 electrons do not come into close proximity, the paired electrons in oxygen occupy the same region of space and have increased repulsion so its easier to remove

Question 33

definition of transition elements (2)

Answer 33

element that has a partially filled d sublevel or can form a stable cation with an incomplete d sublevel

Question 34

why do transition elements have a high melting point

Answer 34

d electrons have high energy and are delocalised, this attraction between the delocalised electrons and metal ions is very strong

Question 35

why is zinc not a transition element

Answer 35

does not form cations with incomplete d sublevel its 4s2 3d10, so it loses 2 electrons but still has an inctact 3d10 sublevel

Question 36

define catalyst

Answer 36

species that reduces the activation energy required for a reaction to occur while not being used up in that reaction

Question 37

define heterogeneous catalysts

Answer 37

type of catalyst that exist in a separate phase to the reactants.

Question 38

how are transition elements used as catalysts

Answer 38

transition elements are used as heterogenous catalysts as gas molecules get absorbed on their solid surface and the molecules undergo chemical changes. the molecules then desorb off the catalyst

Question 39

examples of transition elements used as heterogeneous catalysts and in what?

Answer 39

platinum, palladium and rhodium are used in catalytic converters

Question 40

catalytic converters def + eq

Answer 40

absorb carbon monoxide and oxygen molecules in the exhaust and desorb carbon dioxide 2C0 + 02 = 2C02

Question 41

how do transition elements form variable oxidation states

Answer 41

Transition elements form variable oxidation states because their 4s and 3d electrons have similar energy levels, allowing the removal of different numbers of electrons with low energy differences.

Question 42

ligand definition

Answer 42

molecules or ions with a lone pair of electrons that can be donated to the cation of a transition element to form a coordination bond

Question 43

transition elements forming coloured compounds known as ___ when bonded with ligands

Answer 43

complex ions

Question 44

what happesn when ligands form a coordination bond in terms of orbitals

Answer 44

first, they are degenerate (same energy) then oribitals in the d sublevel are split into 2 sets with different energies the energy gap between the orbitals corresponds to a wavelength within the visible light region of the electromagnetic spectrum

Question 45

how do lower energy oribtals climb to higher energy orbitals in a complex

Answer 45

difference in energy between split orbitals allows lower electrons to be promoted into higher orbitals. the complex absorbs light with a wavelength corresponding to teh energy gap between the non - degenerate orbitals

Question 46

once energy is absorbed what colour is shown in complex

Answer 46

the colour observed is the complementary colour to the colour absorbed

Question 47

complementary colours state

Answer 47

RED GREEN ORANGE BLUE VIOLET YELLO W | Race Goals, Outrun Battles, Victory's Yours."

Question 48

speed formula

Answer 48

speed = frequency x wavelength

Question 49

energy formula

Answer 49

Planck constant (6.63 x 10^-34) x Frequency

Question 50

the larger the splitting between oribtals light shud have?

Answer 50

the greater the energy required to promote the electron for large splitting light should have low wavelength and higher freeq