Question #8bc3b

1 Answer
Jan 17, 2017

Answer:

He changed the periodic table so that it was arranged in order of increasing atomic number, not atomic mass number.

Explanation:

Previously, Dmitri Mendeleev had discovered 63 elements and put them in groups. At that time, he arranged them in order of increasing atomic mass number. Henry Moseley changed the periodic table so that it was arranged in order of atomic number, not atomic mass number.