The chemical equation, KClO3 → KCl + O2, is an example of which type of reaction?

Thermal decomposition reaction

Explanation:

Potassium Chlorate is broken down into Potassium chloride and oxygen gas, as products. Moreover there is only one reactant, proving that it is a decomposition reaction.

it's c (engineer's do their work with mechanical stuff not on any living being)

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.