Stability depends on to proton/neutron ratio; and this ratio increase with the atomic number.
Mendeleev arranged the periodic table according to increasing atomic mass. This method has been used since he first developed it in the 1800s.
He organized the elements by the increasing order of the atomic mass.
in 1869 by Dmitri Mendeleev
The elements on the periodic table are arranged in order of increasing atomic number.
They show that the periodic table isn't arranged on the basis of increasing atomic mass because iodine has a mass lesser than tellurium. Iodine has a mass of 126.90 and tellurium has a mass of 127.60.
Mendeleev arranged the elements in the periodic table according to their atomic masses.
Henry Moseley arranged the elements in order of increasing atomic number rather than increasing atomic mass, which led to the modern periodic table.
Mendeleev arranged the periodic table according to increasing atomic mass. This method has been used since he first developed it in the 1800s.
Towards the bottom, atomic mass increases. Atomic number also increases.
An alpha particle has 2 protons and 2 neutrons. This would make the atomic number decrease by 2 and the Atomic Mass will decrease by 4.
(mass) Density is mass/volume, so increasing the volume with mass held constant will decrease the density.
Mendeleev designed the periodic table by increasing atomic mass. But it was later changed to increasing atomic number.
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 general trend in densities for period 2 elements of the periodic table is that densities increase from left to right. This is because elements in period 2 have increasing atomic numbers, leading to an increase in atomic mass and a decrease in atomic volume, resulting in higher densities.
Neutrons add mass and stability to an atom by increasing the atomic weight without changing the chemical properties. They also help to hold the nucleus together by balancing the repulsive forces between protons.
He proposed one of the early versions of the Periodic Table. He arranged the elements in the increasing order of their increasing Atomic Mass and repeating properties.
Elements are arranged in order of their Proton Number/Electron Number. they are NOT arranged in Atomic Mass , because a given element my have isotopes, which alters the Atomic Mass.