nitrogen dioxide
noun
mass noun
1- Chemistry a reddish-brown poisonous gas formed when many metals dissolve in nitric acid【化】二氧化氮。
1.1
- Chem. formula: NO2. It usually exists in equilibrium with dinitrogen tetroxide, N2O4.化学分子式：NO2. 通常与四氧化二氮[N2O4]以一种平衡状态共存。