/ 5haIdrEdVEn; `haIdrEdVEn/ n [U] (chemistry 化) gas that has no colour, taste or smell and is the lightest substance known, combining with oxygen to form water 氢. =>App 10 见附录10.
# `hydrogen bomb (also `H-bomb) immensely powerful type of bomb which explodes when the nuclei of hydrogen atoms fuse 氢弹.
,hydrogen pe`roxide = peroxide 2.