Supply the missing information in the following table:

Isotopic symbols represent specific isotopes of elements, denoting the element's chemical symbol along with its mass number and atomic number. The mass number, located at the top left, indicates the total number of protons and neutrons in the nucleus, while the atomic number, found at the bottom left, specifies the number of protons, which defines the element.

The atomic number is a fundamental property of an element, representing the number of protons in its nucleus. This number determines the element's identity and its position in the periodic table. For example, gold (Au) has an atomic number of 79, meaning it has 79 protons and, in a neutral atom, also 79 electrons.

The mass number is the sum of protons and neutrons in an atom's nucleus. To find the number of neutrons, subtract the atomic number from the mass number. For instance, in the isotope 198Au, the mass number is 198, and with an atomic number of 79, the number of neutrons is 198 - 79 = 119.