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Why is the atomic mass number not a whole number?
We can find Atomic Mass and mass number in chemical elements. Atomic mass is about weight of the atom. Mass number is about total of neutrons and protons.
What is the relationship btw atomic mass and atomic mass number?
We can find atomic mass and mass number in chemical elements. Atomic mass is about weight of the atom. Mass number is about total of neutrons and protons.
What is the number in front of an element called?
atomic number
What is the number on top of an element called?
The Atomic Number
Who invented piriodic table?
Dmitri Mendeleev created the first periodic table according to atomic mass in 1869. Others before Mendeleev had organized the elements according to their properties and were able to discern periodicity, although Mendeleev is generally accepted as the creator of the table.With the information he gathered about the elements, he was able to see that there were missing elements that hadn't been discovered. He could figure out the atomic masses of the missing elements by averaging the atomic masses of the elements above and below the missing one. One such element, which he called "eka-silicon" (eventually Ge) was missing, but with understanding of the patterns the periodic table made, he predicted the elements appearance, melting point, atomic mass, density, formula of oxide, and formula of chloride.Throughout the years, other scientists were able to find or create these missing elements to form the table we know today. Today's periodic table is ordered by atomic number instead of atomic mass (as Mendeleev had started). Henry Moseley was the first to order the elements by atomic number so elements would fit together in groups/families and periods better in 1913.
