the periodic table

Galileo

Einstein

Mosley

Mendeleev

By increasing atomic number

By decreasing atomic mass

By increasing atomic mass

By decreasing atomic number

Mendeleev periodic table is similar to the one we use now because they both are able to predict properties of undiscovered elements. 

Mendeleev periodic table is similar to the one we use now because they both were not able to predict properties of undiscovered elements. 

Mendeleev periodic and the one today both used the atomic mass number to organize the periodic table.

Mendeleev periodic table and the one today both used the exact same elements.

Periods

Protons

Properties

Levels

by increasing atomic mass

by decreasing atomic mass

by increasing atomic number

by decreasing atomic number

an element.

a group.

an isotope.

a period.