Monatomic
Part of speech: adjective
Definition: Of an element, consisting of a single atom in the molecule; for example: the noble gases. Note: strictly speaking, a molecule has at least two atoms.
Matter
Part of speech: verb
Definition: To be important.To care about, to mind; to find important.
Part of speech: noun
Definition: The basic structural component of the universe. Matter usually has mass and volume.Matter made up of normal particles, not antiparticles. (Non-antimatter matter).A kind of substance.A reason for concern; being amiss.A situation.A cause.Written material (especially in books or magazines)Gray and white matter are the two nerve tissue types that comprise the brain and spinal cord.
Example sentence: It doesn't matter who my father was; it matters who I remember he was.