What element has 53 protons and 74 neutrons?

Question:

Atomic Number and Atomic Mass:

Atomic numbers are the number of protons in an atom. It is always a whole number. Elements on the periodic table are arranged by increasing atomic number. The sum of the number of protons and the number of neutrons in an atom's nucleus is its mass number. In an atom, the mass number is a whole number also.

Answer and Explanation: 1