What is Z in a nuclide?

Z in a nuclide represents the number of protons in the nucleus of an atom. According to the reference material, nuclides are expressed as ^A_ZX, where:

• A is the total number of protons and neutrons (also known as the mass number).
• Z is the number of protons (also known as the atomic number).
• X is the chemical symbol for the element.

Essentially, Z defines which element the nuclide is. For instance, if Z = 6, the nuclide is a form of carbon (C), regardless of the number of neutrons.

Here's an example:

¹²₆C

In this case:

• A = 12 (Total number of protons and neutrons)
• Z = 6 (Number of protons)
• X = C (Carbon)

The number of neutrons can be calculated as A - Z (12 - 6 = 6 neutrons in this example).