Physical involves changes that you can observe and describe matters.
Chemical involves the chemical reaction.
Answer:
1913. Henry Moseley determined the atomic number of each of the known elements. He realized that, if the elements were arranged in order of increasing atomic number rather than atomic weight, they gave a better fit within the 'periodic table'.
Explanation:
GOO
The type of reaction caused by particle accelerators is called photo-fission reaction
Answer:
Any substance that cannot be decomposed into simpler substances by ordinary chemical processes.
Another definition:
An element is the simplest pure substance which can neither be split nor built up from other simpler substances by chemical reaction
