Final answer:
The SO₄²- ion has a tetrahedral electron pair geometry and a trigonal pyramidal molecular structure.
Step-by-step explanation:
The SO42- ion has a tetrahedral electron pair geometry and a trigonal pyramidal molecular structure.
In the SO42- ion, there are 4 electron pairs around the sulfur atom. These include 4 bonding electron pairs and 0 lone pairs. Based on the VSEPR theory, the electron pairs repel each other and try to get as far apart as possible, leading to a tetrahedral electron pair geometry.
In the molecular structure of SO42-, one of the bonding electron pairs is replaced by a double bond with an oxygen atom. This results in a trigonal pyramidal molecular structure, where the sulfur atom is at the center with three oxygen atoms surrounding it.