State modern periodic law. (b) How does the electronic configuration of the atom of an element relate to its position in the modern periodic table? (c) How could the modern periodic law remove various anomalies of Mendeleev's periodic table? Explain with examples. (d) Is it possible to have an element having atomic number 1.5 placed between hydrogen and helium ? Name the scientist who prepared modern periodic table.
ChemistryClass 10ICSEAnswered 27 Mar 2026
Answer
- The modern periodic law states that the properties of elements are a periodic function of their atomic
- The elements are arranged in the increasing order of atomic number and helps in arranging the elements according to their electronic Elements across a period show an increase in the number of valence electrons.
- Anomalies of Mendeleev’s periodic table
- Elements are arranged in increasing order of atomic number in modern periodic table, thus there was no need for keeping more than one element in one slot
- Mendeleev failed to explain the position of isotope where modern periodic table put those in one place in the same group.
- Hydrogen element has been placed at the top of the group 1 above the alkali metals which similar to alkali metals properties.
- Atomic number is always a simple whole It can either be 1 or 2. There can be no element with atomic number 1.5.
- The modern periodic table was prepared by