Question

What two regions make up all atoms?

Answer 1

An atom is the smallest part of any element. Atoms consist of various sub –atomic particles called electrons, protons, neutrons. Electrons are the negatively charged species, while in the center of an atom are the protons and the neutrons, which consist of the nucleus.

Complete answer:
An atom is the simplest part of an element. Various atoms together make up an element. The structure of an atom tells us about the specifications and the regions in it. An atom contains sub –atomic species such as, electrons, protons, neutrons.
According to the latest theory for the structure of an atom called the quantum mechanical model. An atom consists of a positively charged nucleus and the electrons surrounding the nucleus are found in various orbits.
The sub atomic species like protons and neutrons are found inside the nucleus, and thus the nucleus is positive in charge. While the electrons are found in orbits that have various energy levels. The energy of any electron in an orbit is constant, and thus quantized.
Hence, the two regions that make up an atom are, the nucleus where protons and neutrons are found, and the electron cloud which is the orbit in which the electrons are found.

Note:
This quantum mechanical model apart from suggesting the structure of atoms, also tells the particle and wave nature of matter. Before this model, various scientists proposed a model for an atomic structure that also identified a nucleus and the area where electrons are present. Some famous atomic models are, J.J Thomson model, Bohr’s model for an atom, Rutherford’s model, etc.