The mechanism of enzymatic action within a single substance
Electron shell is the outer orbital, while the inner orbital are just called orbitals.
Scientific theories are often so powerful because they have been tested several time by different peoples and they have been found to be true. A scientific theory is a well substantiated explanation for a specific phenomenon which has undergone many observations and experiments and has stand the test of time. Thus, scientific theories always have to be reckon with because they have been severally tested.