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2 components (1 point each):
a: because electrons are negative, valence electron pairs repel one another
b. consequently, atoms bonded to the central atom , and unshared pairs on the central atom, are spread as far apart as possible
electron repulsion
The basis is that like charges repel each other
The basis of VSEPR theory is that electrons carry the same charge, therefore they must repel each other. Which makes them as far apart as possible.
The VSEPR theory states that in a small molecule, the pairs of valence electrons are arranged as far apart from each other as possible
Because negative electrons repel each other, the valence­electron pairs (including shared electron pairs) in a molecule are as far apart from each other as possible.
Title: Jan 29­7:56 AM (1 of 3)
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Because of unshared electrons
One is pyramidal and one is planar. NF3 has unshared pairs of electrons so the atoms are spaced differently than BF
3
NF3 is pyramidal and BF3 is planar. The difference in shape is due to the unshared electron pair on the central atom of NF3 (the central atom is N). NF3 is pyramidal because it has an unshared pair of electrons. BF3 is trigonal planar as it doesn't have the unshared pair. NF3 is trigonal pyramidal and BF3 is trigonal planar. They differ because the electron repulsion from the unshared electrons influences the shape.
Because of the unshared electron on the central atom
NF3is trigonal pyramidal and BF3 is trigonal planar. The unshared electron pair on the central atom (N) of NF3 repels the shared electrons of the N­F bonds. BF3 does not have unshared electron on its central atom. Title: Jan 29­8:11 AM (3 of 3)