What you’ll learn2 learning objectivesChoose one objective for a focused lesson, or study the complete topic.2.1.1Unified atomic mass unit• Define the unified atomic mass unit as one twelfth of the mass of a carbon-12 atomSyllabus objective2.1.2Atomic mass, Ar, isotopic mass• Define relative atomic mass, Ar, relative isotopic mass, relative molecular mass and relative formula mass, both referred to as Mr, in terms of the unified atomic mass unitSyllabus objective