Best Answer: First true and second false.- ... Isotopes of an element have different atomic masses is TRUE. An isotope is an element, say carbon for example, that ...
Absent-mindedness is where a person shows inattentive or forgetful behaviour. It can have three different causes: a low level of attention (blanking or zoning out) intense attention to a single object of focus (hyperfocus) that makes a person oblivious to events around him or her;
adj. 1. Lacking conscious awareness; unmindful: oblivious to her surroundings; oblivious of the criticism against him.