Chapter 7 (periodic properties of elements)

what is effective nuclear charge

how strong valence electrons are attracted to the nucleus

Zeff equation

Z-S

Z=atomic number/number of protons

S=screening by inner electrons; all electrons in lower n levels

across a period (left to right), Zeff…

increases

down a group, Zeff…

increases slightly

down a group, size…

increases

across a period (left to right), size…

decreases

in the d block, there is a gradual ___ in size (d1-d7)

decrease

in the d block, there is a gradual ___ in size (d8-d10)

increase

as the charge of a cation increases, the size…

decreases

as the charge of an anion decreases, the size…

increases

what is ionization energy

energy required to remove an electron

ionization energy ____ down a group

decreases

ionization energy ____ left to right

increases

between Be and B, which has a higher ionization energy

Be

between N and O, which has a higher ionization energy

N

what is electron affinity

energy associated with adding an electron

the greater the attraction between an atom and an added electron, the electron affinity becomes more ____

negative/favorable

as size decreases, electron affinity becomes ____

more negative/favorable

as Zeff increases, electron affinity becomes ____

more negative/favorable

electron affinity ____ across a period

becomes more negative

electron affinity ____ down a group

decreases

does Cl or F have a higher electron affinity

Cl

most first electron affinities are…

exothermic

Second electron affinities are always…

unfavorable

electron affinity for group 2A is

unfavorable

Group 5A have less ____ EA than expected

negative

electronegativity ____ left to right

increases

electronegativity ____ down a group

decreases

most and least electronegative atoms?

F and Cs

High 5 in electronegativity?

N, O, F, Cl, Br

H has a similar electronegativity to…

C

what is lattice energy

the energy needed to completely separate a mole of a solid ionic compound into its ions in the gas phase

as bond length increases, dipole moment…

increases

as bond length decreases, dipole moment…

decreases

as delta electronegativity increases, dipole moment…

increases

as delta electronegativity decreases, dipole moment…

decreases

where does a dipole arrow point

towards the more electronegative atom

lattice energy increases when charges

increase

lattice energy increases when size

decreases

where do partial positive and partial negative signs go

partial positive: less electron dense atom (less electronegative

partial negative: more electron dense atom (more electronegative)