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electronegativity trends across the period and down the group

kandykissesxox

why does E.N INCREASE across a period and increase up the groups?

Thank you!!

Reply 1

charco

Study Forum Helper

Original post by kandykissesxox

why does E.N INCREASE across a period and increase up the groups?

Thank you!!

yeah, the above post in English would say that as the nuclear charge increases across a period but the outer energy level is the same, the radius decreases and the attraction for an electron (or electron density) along a bond is greater.

The electronegativity value is derived from both the electron affinity and the ionisation energy.

Reply 2

It's_Ailie

Original post by kandykissesxox

why does E.N INCREASE across a period and increase up the groups?

Thank you!!

Going across the period, atomic no. increases therefore no. of protons increases therefore nuclear charge increases.
Going up a group there are fewer electron shells so the nucleus is less shielded

Posted from TSR Mobile

Reply 3

hurricaneee

Electronegativity increases across a period as atomic charge increases and the atomic radius decreases, thus the pull on the electrons in greater and the ability to attract electrons in a covalent bond increases.

As we go down a group, shielding increases, lessening the attraction of the politively charged nucleus and negatively charged electrons. This means electrons are more easily lost and therefore these elements can be described as having low electronegativity or can be described as electropositive.