10/4 notes Flashcards
are cations smaller or larger than their neutral atoms
smaller
fewer electrons and they are pulled closer to nucleus
are anions smaller or larger than their neutral atoms
larger
more electrons (further from nucleus due to electron-electron repulsion)
what is first ionization energy
the energy required to pull the first electron (easiest to pull off)from an atom
what are the two kinks with first ionization energy
Be -> B
and
N-> O
what is second ionization energy
energies are always larger than the first IE
3rd ionization energy
always larger than the second, etc
electron affinity (EA)
Energy change when an electron is added to an atom. This produces an anion.
what are the halogens
F, Cl, Br, I
what is a halogen
they have the most negative EA. They are negative because energy is released when the added electron binds to an atom
is the first EA more positive or more negative across a row
more negative (excluding the noble gases)
is there a clear trend down a colum
no
what is noble gases EA
clsoer to zero (sometimes even negative)
what are noble gases IE’s
very high, so hard to pull off electron
when EA’s are close to zero
there is no advantage in adding an electron
why is there a kink between Be and B
B has a valence electron in 2p orbital while Be has one in 2s orbital so it has a lower IE energy
why is there a kink between N and O
Oxygen has additional electron in 2p orbital which causes e-e repulsion and makes it easier to remove an electron than in N atom
Electron-electron repulsions
due to their like charges, electron pairs orient themselves as far away as possible from each other, causing the electron cloud to expand
why are IE always positive
because energy must be supplied (an endothermic energy change) to separate electrons from atoms.
Why are successive I.E.s always larger?
because for the same nuclear charge (positive pull of the nucleus) there are fewer electrons each time one is removed, thus more energy is required to remove successive electrons.
why does a large jump in ionization energy occur
When electrons are removed in succession from an element, the transition from removing valence electrons to removing core electrons
What trends are observed for the first E.A.?
Tend to be negative, meaning energy is released when the electron is added
Why are noble gases unreactive?
they have fully filled outer orbital configuration due to which they are very stable and have minimum energy.
