Final answer:
The distance from an atom to its valence electrons cannot be measured because valence electrons are constantly moving and their exact positions are described probabilistically, not as static distances.
Step-by-step explanation:
You cannot measure the distance from an atom to its valence electrons because valence electrons are constantly moving. Atoms do not physically touch each other due to the repulsion between negatively-charged electrons. In quantum mechanics, electrons behave as particles with no precisely determined location, rather, their positions are best described in terms of a probability cloud where they can be found. The Bohr model suggests that valence electrons are at varying distances from the nucleus based on their energy levels, with higher energy levels being further away. The position of valence electrons influences chemical bonding, but the exact distance is not static and cannot be measured as if they were in fixed orbits.