Question

indicate the possible time scales for each biological, physical and chemical weathering
?

Answer 1

chemical could be minutes or hours, think of sugar in potassium chlorate
https://www.youtube.com/watch?v=EyaFVhC5VPk

biological could be thousands of years like lichen on a rock, or just days like termites eating through a tree


physical could be millions of years, like the Colorado river cutting out the Grand Canyon

Answer 2

i realized you probably meant something more like oxidation for chemical weathering, which can take thousands of years as well