The number found below the name and symbol of an element on most periodic tables. Usually has a decimal, but doesn't have to.
By Atomic Mass
Average atomic mass
Atomic mass is determined by mass spectrometry.
The elements with the highest mass are on the bottom right of the periodic table.
Mendeleev's version of the Periodic Table was organized by increasing mass. The modern periodic table is now organized by atomic number.
By Atomic Mass
he arranged his Periodic Table by each elements Atomic Mass
Average atomic mass
Mendeleev arranged the elements in the periodic table according to their atomic masses.
The periodic table is arranged by atomic mass. Hydrogen is the lightest element. Its atomic mass is one.
Atomic mass is determined by mass spectrometry.
The atomic number is the whole # on the periodic table or the # of protons in an atom. The atomic mass is the # that is not the whole # on the periodic table, or you can multiply the mass of the isotope by its abundance and add the answers together.
The elements with the highest mass are on the bottom right of the periodic table.
Mendeleev's version of the Periodic Table was organized by increasing mass. The modern periodic table is now organized by atomic number.
Mendeleev's table was arranged by atomic mass and the periodic table is arranged by protons (atomic number).
The elements on the periodic table are arranged in order of increasing atomic number.
The modern periodic table is arranged according to the elements' atomic numbers.