The theory of plate tectonics is a relatively new idea, developed in the mid-20th century following the discovery of tectonic features on sea-floors. Can you imagine our explanation of faults, earthquakes, mountains, and rifting before the plate tectonic revolution?

 Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like a hard and rigid shell compared to Earth's mantle.

Explanation:

Plates interact at three types of plate boundaries: divergent, convergent and transform. Most of the Earth's geologic activity takes place at plate boundaries.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.