Question

Help in timed

Scientists improved Mendeleev’s early periodic table by _____.


using numbers of neutrons and protons to organize the elements by their properties

using atomic number instead of atomic mass to organize the elements

including physical properties of elements such as melting point and density

including chemical properties of elements such as the ability to burn or to tarnish

Answer 1

They used atomic number instead Alf and omicron mass

Answer 2

They used atomic # instead of its mass