Flashcards in 1.5 atomic structure and periodic table Deck (16):
a What is relative atomic mass?
the mass of an atom averaged over its isotopes relative to 1/12 of a C-12 atom
a What is relative isotopic mass?
the mass of an isotope relative to 1/12 of a C-12 atom
b What happens within a mass spectrometer?
electron gun knocks electrons out of their shells, creating positive ions
these are accelerated using a negatively-charged plate
a magnetic field deflects them so that they hit detectors at the end
b How are mass spectrometers useful?
more massive particles are deflected less, so the RAM can be found; this allows for one to deduce isotopic composition of an element or RMM of a compound
d Define the term 'first ionisation energy'.
the enthalpy required to form one mole of unipositive gaseous ions from the element in a monatomic gaseous state
g Give the shape of and no. of electrons within
a) an s subshell
b) a p subshell
a) spherical, 2
b) three figures of eight on the xyz planes, 6
g In what order do shells fill up?
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p...
g Describe how the p shell fills up.
first e- goes in one 8-shaped orbital
second and third go in the other two
thence, electrons pair up
h Why is it easier to remove electrons from 4s than 2s?
further from nucleus: less attraction
electron shells between it and nucleus: more repulsion (shielding effect)
h Why is it easier to remove an electron from a p subshell if >3 are present (as opposed to <4)
electrons paired up; repulsive effect within orbital
h What happens when there are 4 or 9 electrons in a d subshell?
one electron is removed from the s subshell below it
i What properties do elements within s/p/d blocks have?
their outermost electron is in an s/p/d subshell
j What is a periodic property?
a quantity for which there is a trend across the periodic table
j What is the trend for atomic radius and why?
increases towards the top-right
going right -> nuclear charge increases
going up -> number of shells decreases
ki What is the trend for melting temperatures in groups 2 + 3 and why?
ionic radius increases
greater distance between nuclei and delocalised electrons