Write an electron-dot structure for each of the following molecules or ions, and predict the geometrical structure: (a) BrO4- (b) ClO3- (c) HIO4 (d) HOBr.

Electron-dot structures, also known as Lewis structures, represent the valence electrons of atoms within a molecule. They illustrate how electrons are shared or transferred between atoms, helping to visualize bonding and lone pairs. Understanding how to draw these structures is essential for predicting molecular geometry and reactivity.

Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs around a central atom. According to VSEPR, electron pairs will arrange themselves to minimize repulsion, leading to specific shapes such as linear, trigonal planar, or tetrahedral. This theory is crucial for determining the three-dimensional arrangement of atoms in a molecule.

Formal charge is a concept used to determine the distribution of electrons in a molecule or ion. It is calculated by comparing the number of valence electrons in the free atom to the number of electrons assigned to it in the Lewis structure. Understanding formal charge helps in assessing the stability of a structure and in identifying the most favorable resonance forms.