How do atoms of different elements primarily differ?

Atoms of different elements primarily differ in their number of subatomic particles, which include protons, neutrons, and electrons. The number of protons in the nucleus of an atom defines the element itself and determines its atomic number, which is unique for each element. For example, hydrogen has one proton, while carbon has six. The number of electrons, which balance the positive charge of protons, also affects how atoms interact with each other, influencing their chemical behavior and bonding properties.

While atomic mass and chemical properties are certainly important aspects of elements, they stem from the differences in subatomic particle numbers. Atomic mass is derived from the total number of protons and neutrons, and chemical properties are influenced by the electron arrangement around the nucleus, which is directly influenced by the number of protons. Physical states (solid, liquid, gas) depend more on conditions like temperature and pressure rather than the inherent differences between the types of atoms themselves. Thus, the primary distinction among different elements lies in the number of subatomic particles they contain.