Atomic number is denoted by ____________.

Z

Atomic number is denoted by the symbol Z. It represents the number of protons in the nucleus of an atom. This number is unique for each chemical element and determines its chemical properties.

Here's a breakdown of the concept:

• Proton: A positively charged subatomic particle found in the nucleus of an atom.
• Atomic Number (Z): The number of protons in an atom's nucleus.
• Significance of Atomic Number:
  • Element Identity: It defines the element. For instance, all atoms with 6 protons are carbon atoms.
  • Periodic Table Organization: Elements are arranged in the periodic table based on their atomic numbers.
  • Chemical Properties: The number of protons influences an atom's electron configuration, which in turn determines its chemical behavior.

Therefore, the atomic number (Z) is a fundamental property of an atom that characterizes its identity and chemical properties.

For example, ₂He⁴, Z = 2.