The average person's idea of the size of an atom varies, but it is commonly perceived as being extremely small. Many people envision atoms as tiny solid spheres or microscopic particles. However, the true scale of an atom is far smaller than what our intuition might suggest.
Atoms are the basic building blocks of matter, and they consist of a nucleus at the center, which is surrounded by a cloud of electrons. The nucleus contains protons and neutrons, while the electrons orbit around it.
To give you a sense of scale, the typical diameter of an atom ranges from about 0.1 to 0.5 nanometers (1 nanometer is equal to one billionth of a meter). If we were to compare the size of an atom to other objects, a simple analogy often used is that if an atom were the size of a football stadium, the nucleus would be roughly the size of a fly in the center.
It's important to note that this analogy is only meant to illustrate the relative scale, as atoms are not solid objects with distinct boundaries. They are quantum mechanical entities with a wave-like nature, and their precise size and position are described by probability distributions.
Overall, the average person's idea of the size of an atom is often a simplified and abstract representation, but understanding the true scale requires knowledge of the atomic structure and the principles of quantum mechanics.