7.12 periodic trends in atomic properties Flashcards
what is ionization energy
energy required to remove an eletron from a gaseous atom or ion
what is the first ionization energy
energy required to remove the highest energy electron (the lowest)
why is the second ionisation energy conciderably biger than the second?
This can be linked to charge. The second ionisation energy will act on a 1+ atom, since 1 electron has already been removed. Therefore, the second electron is more firmly bonded to the nucleus than the first one.
what happens to the first ionization energy when going towards the right of the periodic table
the first ionization energy increases, With an increasing nuclear charge, attraction is stronger
what happens to the first ionization energy when going down a group
it decreases, since the size increases (more electronic layers) , the valence electrons are being removed further from the nucleous, therefore not bounded as strongly
what can cause an exception to these rules
electron shielding: when an orbital is filled, electrons are shielded from nuclear pull because of the atraction they have to each other
how to calculate ionization energy
Photoelectron spectroscopy
E elecontron = hv - KE
what is electron affinity
the energy change associated with the addition of an electron to a gaseous atom
is the value positive or negatve
negative, the more negative the greater quanity of energy released
how does electron affinity vary in periodic table
generally, become more negative from left to right in periodic table
many exceptions,
how can atomic radii be determined
by measuring distance between 2 nuclei in covalent compounds and dividing them (Br2) p.290
(covalent atomic radii)
metaliic radi: measured by half the distance in solid metal crystals
How does the atomic radii vary in the periodic table
gets smaller from left to right
bigger up down in same family
