Atoms of the same element that have different masses are called isotopes. Different masses result when there are different numbers of neutrons. All atoms of a particular element have the same number...
Definition of absent. 1 : not present at a usual or expected place : missing was absent from class today sharing memories of absent friends She was conspicously absent [=her absence was very noticeable] at the meeting. absently. adverb He replied absently to her question. Examples of absent in a sentence.
singular. 1  extraordinary - beyond what is ordinary or usual; highly unusual or exceptional or remarkable; extraordinary authority; an extraordinary achievement; her extraordinary beauty; enjoyed extraordinary popularity; an extraordinary capacity for work; an extraordinary session of the legislature.