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Limitations of modern periodic table?? |
| Answer» Yes there are some defects of modern periodic table they are given below 1.No proper position to lanthanoids and actinoids.2.Position of helium is not justified :based on electronic configuration helium should be placed in group two along with alkaline earth metals but it has been placed with group eighteen along with noble gases based on its properties 3.Position of hydrogen:the position of hydrogen still remains controversial as it resembles alkali metals in its electronic configuration so it can be placed in group one but it also resembles the properties of halogen so it can be placed in halogens but hydrogen differ from both alkali metals and halogens in many other properties however for convenience it is usually placed in group and period one due to lowest atomic mass and atomic number . | |