What does the atomic number of an element represent?

The atomic number of an element is defined as the number of protons found in the nucleus of an atom of that element. This number is fundamental because it determines the identity of the element; for instance, all hydrogen atoms have an atomic number of 1 because they each contain one proton, while all carbon atoms have an atomic number of 6 due to having six protons. The atomic number also plays a key role in the arrangement of elements in the periodic table; elements are organized in order of increasing atomic number.

This characteristic is crucial for understanding the chemical properties and behaviors of elements. For example, the atomic number affects the electron configuration, which in turn influences how an element interacts with other elements in chemical reactions. Therefore, knowing the atomic number provides insights into the element's reactivity, bonding capacity, and position in the periodic table.