CH 7: Periodic Properties of the Elements Flashcards
Atomic radius _________ across a period
Decreases (until noble gases)
Atomic radius _________ down a family
Increases
Zeff =
Effective nuclear charge
Z-S
Within Zeff, Z =
Nuclear charge (Atomic number)
Within Zeff, S =
Shielding (e- in inner shells)
Zeff within a family is _________
The same. But the force of attraction decreases as the atoms get larger
Ionization Energy
The energy required to remove an e-
IE _________ across a period
Increases
IE _________ down a family
Decreases
In general, larger atoms have lower IE because…
Larger atoms have increased shielding, so it’s easier to take an e-
Element with highest IE is ___
He, because it’s e=very small and has no shielding
Electron Affinities
The attraction an atom has for an e-
The more negative an EA…
The more favorable the process (ex. Halogens have the most negative EAs, so they have the greatest affinities)
Element with highest EA IS ___
Cl. The expected highest is F, but F is so small that repulsion affects the energy change
EA _________ across a period
Increases (Gets more negative)
