Periodic trends in atomic properties and inter-atomic bonds

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How does the atomic radii change down a group?
It increases.
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How does the atomic radii change across a period?
It decreases.
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Explain the trend in atomic radii as # electron shell increases
It increases the atomic radius (down a group)
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Explain the trend in atomic radii as nuclear charge increases
It decreases the atomic radius; (along a period)
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Explain the trend in atomic radii as shielding effect increases
It increases the atomic radius (as it reduces the effect of the Nuclear charge)
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Define 'Effective nuclear charge' (Z_eff) and give the equation
The net positive charge experienced by an electron in a poly-electronic atom; Z_eff = Z-S (where Z is the # protons in the nucleus and S is the #of shielding electrons calculated using Slater's rule
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Define Ionisation energy
Energy needed to remove an electron from a gaseous atom to form a cation
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How does the size of an atom affect the Ionisation energy?
I.E decreases with increasing size as the attraction of the electron to the nucleus falls.
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How does nuclear charge affect the Ionisation energy?
They are proportional so as it increases so doe I.E.
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How does a screening/shielding affect the Ionisation energy?
It reduces the attraction so the I.E falls as it increases.
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How does the penetration effect affect the Ionisation energy?
s- electrons experience more attraction than p,d and f so I.E decreases from s. (s>p>d>f)
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How does electron configuration affect the Ionisation energy?
If atoms have a stable configuration then the I.E is high. Paired electrons are removed easily due to repulsion so I.E is lower.
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Explain the trend in successive I.E
Removal of each successive electrons needs more energy as the inner electrons experience a greater force of attraction so I.E increases. There could be large increase when removing core electrons / electrons from a different orbital
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What happens across a period (in terms of I.E)?
I.E increases
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What happens up a group (in terms of I.E)?
I.E increases
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Define electron affinity
Energy released when an electron is added to an atom
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Give the equation to work out the net bonding force
F_N = F_A +F_R (where A is attractive and R is repulsive)
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When do each type of force involved in bonding dominate?
R: dominates at smaller distances; A: at larger distances
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Define bonding energy
The energy required to separate two atoms to an infinite separation. (denoted E_0)
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Other cards in this set

Card 2

Front

How does the atomic radii change across a period?

Back

It decreases.

Card 3

Front

Explain the trend in atomic radii as # electron shell increases

Back

Preview of the front of card 3

Card 4

Front

Explain the trend in atomic radii as nuclear charge increases

Back

Preview of the front of card 4

Card 5

Front

Explain the trend in atomic radii as shielding effect increases

Back

Preview of the front of card 5
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