Mass number is an integer (whole number) equal to the sum of the number of protons and neutrons of an atomic nucleus. In other words, it is the sum of the number of nucleons in an atom.What is the definition of measurement in chemistry?
Measurement is a process of experimentally obtaining the value of a quantity. The quantity that we intend to measure is called measurand. In chemistry the measurand is usually the content (concentration) of some chemical entity (molecule, element, ion, etc) in some object.What is the mass number for Dy in chemistry?
Symbol: Dy Atomic Number: 66 Atomic Mass: 162.5 amu Melting Point: 1412.0 °C (1685.15 K, 2573.6 °F) Boiling Point: 2562.0 °C (2835.15 K, 4643.6 °F) Number of Protons/Electrons: 66 Number of Neutrons: 97 Classification: Rare Earth Crystal Structure: Hexagonal Density @ 293 K: 8.536 g/cm 3 Color: Unknown Atomic StructureWhat is the mole concept in chemistry?
Mole Concept. In chemistry the mole is a fundamental unit in the Système International d'Unités, the SI system, and it is used to measure the amount of substance. This quantity is sometimes referred to as the chemical amount. In Latin mole means a "massive heap" of material.