p block Flashcards
what does “maximum 4 covalent bonds” mean
2nd period are restricted to 2s and 2p, 3rd or heavier have d orbitals available, can form more than 4 bonds, weaker bond, EA increased
presence of oxygen and alkali metals
cations (M+) in combination with:
O^2- (oxide), O2^2- (peroxide), or O2^- (superoxide)
*atoms prefer to find ox atom that matches in size
what does “greater prosperity for multiple bonds” mean
for multiple bonds, pi overlap of p orbitals must be effective, this is more likely to happen on a pair of 2p orbitals than diffuse 3p (larger) atoms, therefore the 3p have lower higher EA, lower IE, weaker
boron properties
g13, metalloid with covalent network structure, hard, black, high melting point
aluminium properties
g13, typical metal, moderate melting point (represents elements), extended structure
trend of ionic radius in G13
has a 3d subshell, electrons are more poorly shielded, higher Zeff, radius decreases
common oxidation states for G13
most common is +3, going down a group, +1 becomes possible for Ga, In, and Ti, due to inert pair effect (reluctancy to participate in bonding)
natural sources of boron
borate minerals, extracted through reduction, ox state of 3+,
industrial applications of boron
boric acid: white solid, disinfectant, insecticide, fiberglass
boron: resistant to thermal shock, cookware, lab glass
industrial application of aluminium
most abundant in earths crust, can be extracted 2 ways
reduction: required melting at high temperatures
hall-heroult: addition of cryolite, lowered melting point
applications of aluminium
strong, lightweight alloy, resistant to corrosion when anodized, can be recycled, valuable for transportation, construction, consumer packaging
G15 element properties
pnictogens, attain states from -3>+5
going down a group neg ox state becomes less stable, +3 becomes only common for B
nitrogen properties + applications
80% of atmosphere, filtrated, fractional distillation, highly unreactive, good for packaging food, manufacturing electronic decies, science experiment, used as cryogen to store temperature sensitive materials
phosphorous properties + applications
most important allotropes: white and red
phosphate minerals, used as fertilier, extracted through reduction
white phosphorous
white, waxy, highly toxic, low MP
tetrahedral p4 clusters, bond angle 60º (strained), highly reactive, nonpolar, ignites on contact with air, stored underwater
red phosphorous
red, nontoxic, high melting point
polymeric chains, not strained, less reactive, illegal manufacturing meth, striking surface of match boxes
ammonia (nh3)
colourless gas, forms weak base
prepare through haber process, fertilizer
phosphine
cph3, colourless, highly toxic gas, no bronsted lowry basic properties but can act as lewis base, rat poison,
dinitrogen monoxide
colourless, sweet smelling gas, dental anesthetic or rec drug, aerosol for whipped cream
nitrogen monoxide
colourless gas, reacts with ox at high temps in car engines or lightning, important for neural transmissions
nitrogen dioxide
orange-brown toxic gas, produced fron NO due to radical reactions with O2 in atmosphere, leads to NO3-, excess produced from car engines, leads to pollution
tetraphosphorus hexaoxide
white, waxy solid, forms when P reacts with limited oxygen, tetrahedral arrangement of P atoms with 6 bridging atoms
tetraphosphorus decaoxide
white solid, , reacts with excess oxyge, tetrahedral with 6 bridging and 4 terminal O
nitrous acid
weak acid, +3 ox state, useful reagent in organic solutions
nitric acid
strong acid, ox state +5, ostwald process: oxidation of ammonia followed by disproportionate reactions, major application with ammonia for ammonia nitrate (fertilizer)
phosphorus acid
weak acid, +3 ox state, diprotic
phosphoric acid
weak acid, +5 ox state, triprotic acid, starting material for fertilizers
G16 elements
calgogens, ox state from -2,+6, positivef is more stable down the group, industry in semiconductors
dioxygen, O2
normal, colourless gas, low BP, 21% of atmosphere, paramagnetic
ozone (trioxygen)
pungent, diamagnetic, low BP, pale blue, low concentrations in upper atmosphere, low atmosphere is considered pollution
sulfur
more allotropes than any other element, tendency to form bonds to itself
yellow sulfur
stable at room temp, yellow, cyclic 8 crown shape, deposits of earths crust or minerals, fossil duels are contaminated (removed to avoid combustion), oxidized to O3 which can combine with moisture to form acid rain, major application is sulfuric acid, most important in industry (used as strong acid) (strong dehydrating agent)
