An atom is composed of protons, neutrons, and electrons. The protons and neutrons are located in the nucleus, while the electrons orbit the nucleus. The number of protons in an atom defines the element.
An atom is the basic unit of all matter. It is composed of three main subatomic particles: protons, neutrons, and electrons. The protons and neutrons are located in the center of the atom, called the nucleus, while the electrons orbit the nucleus in energy levels or shells. The number of protons in an atom determines its atomic number and defines the element. For example, an atom with one proton is hydrogen, while an atom with six protons is carbon.