GENERAL KNOWLEDGE

Detailed explanation-1: -Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons.

Detailed explanation-2: -Dysprosium atom is a lanthanoid atom and a f-block element atom. An element of the rare earth family that has the atomic symbol Dy, atomic number 66, and atomic weight 162.50.

Detailed explanation-3: -The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.