Final answer:
The atomic radius is defined as one-half the distance between the nuclei of two identical atoms bonded together. For example, if the distance between two Po atoms is 336 pm, the atomic radius would be 168 pm.
Step-by-step explanation:
Half the distance between two identical atoms is known as the atomic radius. This measurement is particularly relevant in the case of atoms that are covalently bonded to each other. In the context of a diatomic molecule, such as a molecule consisting of two polonium (Po) atoms, the atomic radius can be expressed in picometers (pm). If, for example, the edge length of a cell made up of two touching Po atoms is 336 pm, then the atomic radius of Po would be half of this distance, or 168 pm, which can be calculated using the formula r = d/2, where r is the atomic radius and d is the distance between the nuclei of the two atoms.
The atomic radius is often used to describe the size of atoms, and it is defined as one-half the distance between the nuclei of two identical atoms when they are joined by a covalent bond. This helps to standardize the way in which the sizes of atoms are measured, despite the fuzzy and variable nature of orbital boundaries.