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.
Definition of antique. 1 : existing since or belonging to earlier times : ancient antique trade routes to India. 2a : being in the style or fashion of former times antique manners and gracesb : made in or representative of the work of an earlier period antique mirrors; also : being an antique. 3 : selling or exhibiting antiques an antique show.