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Name:   Angela T.
Status:  student
Age:  16
Location: N/A
Country: N/A
Date: 2000
Question:
Why is the electron affinity of the 2a family members such as Be are so highly endothermic or positive?

Replies:
Electron affinity is a measure of the attraction an element has for an electron. Those elements that have a high attraction for electrons, to form a closed shell in the case of the halides have a more negative (i.e. exothermic) energy. They "want" to attract an electron. Metals on the other hand, especially those in group I and II have very little propensity to gain an electron and form an anion. To the contrary they readily LOSE electrons to form cations.

Hence, their endothermic electron affinity.

Vince Calder


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