Cual es la relacion entre difusión y transporte pasivo ​

Silica, sio2, is formed on silicon as an electrically insulating layer for microelectronic devices. silica is formed when silicon is exposed to o2 gas at an elevated temperature. at 900˚c, it takes 90 minutes for the oxygen to diffuse from the surface to form a 0.06 micron (0.06 x 10-6 m) thick layer of sio2 on

Why is it incorrect to balance a chemical equation by changing the subscripts? explain.

Can anyone answer these questions? ? i need it before 1: 00pm today