Periodictable - Questions

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Variation of I1 with Z

Slide 66

Across a period (row), I1 mainly increases with increasing Z.

Because of increasing nuclear charge (Z)

Variation of I1 with Z

Slide 67

Arrange in order of increasing I.E.

N, O, F

Li, K, Cs

Cl, Br, I

Slide 68

Electron affinity

Electron affinity is energy change when an e- adds to a gas-phase, ground-state atom

Energy associated with this reaction:

Positive EA means that energy is released, e- addition is favorable and anion is stable!

First EA’s mostly positive, a few negative

Slide 69

Trends in electron affinities

Decrease down a group and increase across a period in general but there are not clear cut trends as with atomic size and I.E.

Nonmetals are more likely to accept e-s than metals. VIIA’s like to accept e-s the most.

Slide 70