Final answer:
Lightning converts atmospheric nitrogen (N₂) into nitrogen oxides (NOx), which are then dissolved in rain to form nitrates (NO₃⁻), a process known as atmospheric fixation.
Step-by-step explanation:
When lightning strikes, the high temperatures and pressures it generates are sufficient to break the strong triple bonds of atmospheric nitrogen (N₂) molecules. This allows the nitrogen atoms to react with oxygen, leading to the formation of nitrogen oxides (NOx), such as nitric oxide (NO) and nitrogen dioxide (NO₂).
These nitrogen oxides can then dissolve in rainwater to form nitrates (NO₃⁻), which are compounds that can be utilized by plants. This process is a part of the natural nitrogen cycle known as atmospheric fixation.
The other options provided – nitroglycerin, ammonia, and bacteria – are not directly formed by the process of lightning.
While lightning can contribute to the formation of ammonia (NH₃) indirectly, by initiating the subsequent reactions that occur in the atmosphere, the direct conversion caused by lightning involves the creation of nitrogen oxides.