What effect does one unbonded pair of electrons have on the shape of a molecule?

Answer 1

Lone pairs will repel slightly more than bond pairs of electrons. Each lone pair will reduce the bond angle expected by around 2.5 degrees, as a general guide. For example, water has four sets of electrons, so if it had those arranged as in methane, which has four bond pairs, we'd expect the bond angle to be 109.5 degrees. However, the lone pairs repel more, decreasing the bond angle down to 104.5 degrees. The theory is called VSEPR theory and is well explained in the excellent website Chemguide.

Answer 2

Valence shell electron pair repulsion theory says that all pairs of valence (outer shell)electrons around the central atom will repel one another so as to be as far apart as possible. So in methane CH4 the four shared pairs repe one another to the corners of a tetrahedron. In ammonia there are three shared pairs between the nitrogen and the hydrogens and one lone pair. The lone pair is closer in to the central atom than the shared pairs are, so it repels slightly more. This pushes the bond angle down from the tetrahedral angle of 109.5 to 107 degrees. In water there are two shared pairs so the angle is decreased a little more down to 104 degrees. If you Google VSEPR you will find a good explanation and some diagrams quite easily.

Answer 3

An unbonded pair of electrons, also known as a lone pair, can influence the shape of a molecule by repelling other bonded pairs. This can result in distortions from the ideal bond angles, leading to deviations from standard molecular geometries. The presence of lone pairs is particularly important in determining the geometry of molecules with central atoms that possess one or more lone pairs.

Answer 4

you know what it is?

black and yellow black and yellow black and yellow black and yellow

Answer 5

by make more molecules and mor powa!

Answer 6

The bonding angles are modified.