Question

explain electron afinity,electronegativity electron positivitity and metal and non metal How there properties vary in a group and period​

Answer 1

Electron Affinity:

The amount of energy released when an electron is added to the valence shell of an isolated gaseous atom is called Electron Affinity.

$Electron\: Affinity \propto {Z}_{eff} \propto \dfrac{Positive\:charge}{Negative \: charge}$

• Across a period, (left to right) Electron Affinity increases

• Down a group Electron Affinity decreases.

• But the EA of 3rd Period elements is greater than EA of 2nd Period elements.

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Electro negativity:

It's variation is same as EA.

$Electronegativity \propto {Z}_{eff} \propto \dfrac{Positive\:charge}{Negative \: charge}$

• Across a period, (left to right) Electronegativity increases

• Down a group Electronegativity decreases.

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Electropositivity:-

$Electropositivity \propto \dfrac{1} {Z}_{eff} \propto \dfrac{Negative\:charge}{Positive \: charge}$

• Across a period, (left to right) Electropositivity decreases

• Down a group Electropositivity increases.

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Non-metallic character:

$Non-Metallic\: Character \propto {Z}_{eff} \propto \dfrac{Positive\:charge}{Negative \: charge}$

• Across a period, (left to right) Non-metallic character increases

• Down a group Non-metallic character decrease

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Metallic Character:

$Metallic\: Character \propto \dfrac{1} {Z}_{eff} \propto \dfrac{Negative\:charge}{Positive \: charge}$

• Across a period, (left to right) metallic character decreases

• Down a group Metallic character increases.