A black powder, FeO, used in making steel and glass.
- ‘During that period of time, moisture was continually trying to convert them to ferrous oxide.’
- ‘All fertilizer salts react the same way, whether they're potassium chloride, ammonium nitrate (NH.sub.4] NO.sub.3] or ferrous oxide (FeO).’
- ‘The other thing I've done today is register myself as an organisation in order to get me a catalogue for buying ammonium ferrous oxide crystals.’
We take a look at several popular, though confusing, punctuation marks.