D−

Alternative forms

 * D−
 * D-

Etymology
D + −

Symbol

 * 1)  the first negative ion of deuterium

Coordinate terms

 * D+ &mdash; the positive ion of deuterium
 * &mdash; neutral deuterium radical
 * H− (H-) &mdash; the first negative ion of protium
 * &mdash; neutral protium radical
 * H+ (p) &mdash; the positive ion of protium
 * T− (T-) &mdash; the first negative ion of tritium
 * &mdash; neutral tritium radical
 * T+ &mdash; the positive ion of tritium
 * H− (H-) &mdash; the first negative ion of hydrogen
 * &mdash; neutral hydrogen radical
 * H+ &mdash; the positive ion of hydrogen

Pronunciation

 * as "D minus"

Noun

 * 1) An academic grade given by certain institutions. Slightly better than an F+ and slightly worse than a D. D minuses are the lowest passing grades.

Coordinate terms

 * D+, D