The reaction 2kclo3 (s) -> 2kcl (s) + 3o2 (g) is a

(C) Decomposition reaction

Explanation:

A decomposition reaction is a chemical reaction in which a single compound breaks down into two or more compounds or elements.

in this example

Potassium chlorate (KClO₃) decomposed to two smaller compounds KCl and O₂ gas.

So, the right choice is (C) Decomposition reaction

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.