The periodic table is a helpful tool that shows important details about different elements. Two key pieces of information it provides are atomic numbers and mass numbers.

1. Atomic Number (Z):

   • The atomic number tells us how many protons are in the center of an atom.
   • This number also shows the element's identity. For example, Hydrogen has an atomic number of 1, which means it has 1 proton. Carbon has an atomic number of 6, meaning it has 6 protons.

2. Mass Number (A):

   • The mass number is the total number of protons and neutrons in an atom.
   • We can find it using the formula: Mass Number (A) = Atomic Number (Z) + Number of Neutrons (N).
   • For example, Carbon has different types called isotopes. Carbon-12 has a mass number of 12, while Carbon-14 has a mass number of 14.

3. Summary:

   • The atomic number is important because it helps define how the element behaves chemically.
   • The mass number helps us learn about isotopes and how stable they are.