typical gchem question

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teefRcool

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rank the following in order of ionization energy?

Na, F, Cs, Xe

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Xe is the highest ionization energy. electron affinity and electronegativity are zero for noble gases.
 
Cs< Na< F< Xe Cs is always the lowest and Xe is the highest in this case.

"The first ionization energy increases as you move left to right across a row (period) of the periodic table (due to increasing effective nuclear charge).

2. The first ionization energy decreases as you move down a column (group) of the periodic table.

3. The s & p block elements show a larger range of 1st IE than the d and f block elements.

These trends are exactly opposite of those observed for atomic radius. This correlation is no coincidence. The outermost electrons in small atoms such as He are located close to the nucleus, which results in a strong Coulombic attraction. Thus it takes a lot of energy to remove an electron from a small atom, so these atoms have high first ionization energies. Conversely, the outermost electrons in large atoms are located farther away from the nucleus, this leads to a decreased attraction with the nucleus and a smaller first ionization energy.
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Ionization Energy increases when,
there is stronger nuclear charge

there is a full subshell (therefore the atom is stable)

there is a half full subshell therefore there is evenly distributed charge in the atom.

Ionization Energy is low when,
there is more shielding

the electron to be removed is spin paired (therefore there is repulsion)
the electron is far from the nucleus"
 
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