Question

Q4. (a) State Mendeleev's Periodic law.​

Answer 1

Answer:

Mendeleev's Periodic law.

➩the law that the properties of the elements are periodic functions of their atomic numbers. Also called Mendeleev's law. (originally) the statement that the chemical and physical properties of the elements recur periodically when the elements are arranged in the order of their atomic weights.

➩²¹ᵀʰˣ ᶠᵒˡˡᵒʷ ⁻ ᴵⁿᵇᵒˣ

Answer 2

Explanation:

The law that the properties of the elements are periodic functions of their atomic numbers.

Also called Mendeleev's law. (originally) the statement that the chemical and physical properties of the elements recur periodically when the elements are arranged in the order of their atomic weights.

The major difference is that the elements in Mendeleev's periodic table were arranged by atomic mass and the modern periodic table arranges elements by atomic number.

He was unable to locate hydrogen in the periodic table.

Increase in atomic mass was not regular while moving from one element to another.

Hence, the number of elements yet to be discovered was not predictable.

Later on, isotopes of elements were found which violated Mendeleev's periodic law.