1. Atomic Number (Z): The atomic number of an element is equal to the number of protons in its nucleus. Each element has a unique atomic number, which identifies the element.
2. Mass Number (A): The mass number of an element is the sum of the number of protons and neutrons in its nucleus. Knowing the mass number and atomic number allows us to calculate the number of neutrons.
3. Number of Neutrons (N): To find the number of neutrons, subtract the atomic number (Z) from the mass number (A):
$$ N=A-Z$$
For example, consider the element Carbon (C):
- Atomic Number (Z): 6 (Carbon has 6 protons in its nucleus)
- Mass Number (A): 12
To determine the number of neutrons, we subtract the atomic number from the mass number:
$$ N=A-Z= 12 -6 = 6 $$
Therefore, the Carbon atom has 6 neutrons in its nucleus.
