what is the electron geometry of F^2, HF ?
To determine the electron geometry of a molecule, we need to consider the arrangement of all the electron pairs around the central atom. This includes both bonded electron pairs (from covalent bonds) and lone pairs (non-bonded electron pairs).
For F₂, the central atom is fluorine (F), and since each fluorine atom is bonded with a single bond to another fluorine atom, we have a linear molecular geometry. Therefore, the electron geometry of F₂ is linear.
For HF, the central atom is also fluorine (F), and it is bonded with a single bond to a hydrogen atom. Fluorine has 7 valence electrons, and with the additional electron from the hydrogen atom, it has a total of 8 electron pairs. There are two pairs involved in bonding (one with hydrogen and another with another fluorine atom, assuming this is a larger molecule), leaving 6 lone pairs.
In this case, the electron pair geometry is octahedral, which indicates six electron pairs arranged around the central atom. However, we only have 2 bonding pairs and 6 lone pairs. Since lone pairs repel more strongly than bonding pairs, they tend to spread out more, resulting in a trigonal bipyramidal molecular geometry. So, the electron geometry of HF is trigonal bipyramidal.
It's worth noting that the electron geometry refers to the arrangement of all electron pairs (both bonding and lone pairs), while the molecular geometry specifically refers to the arrangement of atoms in a molecule, considering only the bonding pairs.