Final answer:
In today's atomic model, electrons are located in orbitals, which are regions of space around the atom's nucleus determined by their energies and represented in a probabilistic manner via the electron cloud concept.
Step-by-step explanation:
In the current model of the atom, the electrons are located in the regions of space known as orbitals around the nucleus. These orbitals are determined by the electrons' energies, thus the position of an electron can be described as a probability distribution within an electron cloud, rather than a specific orbit. The nucleus, consisting of protons and neutrons, is the positively charged center of the atom and comprises nearly all its mass, although it is very small compared to the rest of the atom. This model is a significant departure from the earlier planetary model and aligns with the principles of quantum mechanics, which state that we cannot know the exact positions of electrons at any given time, just the likelihood of finding an electron in a particular area.