On the Periodic Table each element will have 2 numbers. One will be a whole number going from 1 hydrogen to 113 or so. This is the atomic number which is the number of protons it has. There will also be a number with a few decimal places. Carbon has a atomic number of 6 (as it is element number 6 and has 6 protons.) and an Atomic Mass of 12.011. The atomic mass is the average mass of a an atom for Carbon 99% of the atoms have a mass 12 (6 protons and 6 neutrons) and 1% has a mass of 13 the average of the two (0.99 X 12) + (0.01 X 13) = 12.011
By Atomic Mass
The elements on the periodic table are arranged in order of increasing atomic number.
Mendeleev's version of the Periodic Table was organized by increasing mass. The modern periodic table is now organized by atomic number.
periodic table
before it there was no organization, but the first periodic table was organized by atomic mass.
By Atomic Mass
The elements on the periodic table are arranged in order of increasing atomic number.
Mendeleev arranged the elements in the periodic table according to their atomic masses.
elements atomic mass and number
atomic mass.
By Atomic Mass
Mendeleev arranged the elements in his periodic table in order of increasing atomic mass while also grouping elements with similar properties together. His periodic table laid the foundation for the modern periodic table we use today.
The modern periodic table is arranged according to the elements' atomic numbers.
Mendeleev's version of the Periodic Table was organized by increasing mass. The modern periodic table is now organized by atomic number.
Atomic number and atomic mass
periodic table
by Atomic Mass