The atoms of different elements differ primarily in three key ways: the number of protons, the number of neutrons, and the arrangement of electrons.
Firstly, the most fundamental difference lies in the number of protons found in the nucleus of an atom. Each element has a unique atomic number, which corresponds to the number of protons it possesses. For example, hydrogen has one proton, while helium has two. This difference in proton count is what defines the element itself.
Secondly, while the number of protons determines the element, the number of neutrons can vary within atoms of the same element, leading to the formation of isotopes. For instance, carbon typically has six neutrons, but there are isotopes of carbon with seven or eight neutrons, which are still carbon but have different atomic masses.
Lastly, the arrangement of electrons surrounding the nucleus also varies among different elements. Electrons occupy specific energy levels, and the distribution of these electrons affects how atoms interact with one another. The electron configuration influences an element’s chemical properties and reactivity.
In summary, atoms of different elements differ in the number of protons, the presence of neutrons (in the case of isotopes), and the arrangement of electrons. These variations are fundamental to the diversity of chemical behavior observed across the periodic table.