It's pretty common for things to react as liquids and solids, but they can also react as gases. To show this I just need some hydrochloric acid and ammonia.

Hazardous gases discovered at Canandaigua home; ammonia discovered during early morning incident Saturday ...

The development by the Department of Polymer Materials Engineering at Shenkar is part of the "Future Soldier" project funded ...

With good sensitivity, selectivity, and stability, this technology addresses long-standing challenges in air quality monitoring, industrial safety, and environmental protection—promising a safer, ...