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.
A woman holding several presents and gift wrap. The definition of present is someone or something that is at a specified place. An example of present is a group of people that is already in a conference room for a meeting. Present is current time or is happening right now.