Q1 of 52 Page 38

Upto which element, the Law of Octaves was found to be applicable.

John Alexander Reina Newland was the first to discover the Periodic Table. He made a table of all known elements and arranged them on the basis of their atomic weight. Lithium is the first element and sodium is the eighth element. Similarly, the eighth element after sodium is potassium. Law of octaves says that the elements Li, Na and K must have similar chemical and physical properties. For example, if we start from Lithium (atomic mass = 6) and arrange elements in increasing order of their atomic masses, the eighth element will be sodium (atomic mass = 23). Both elements show the same physical and chemical properties.
This classification was not applicable to all elements. It was only valid for elements having atomic masses lower than Ca.

More from this chapter

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2

According to Mendeleev's Periodic Law, the elements were arranged in the periodic table in the order of

 3

In Mendeleev’s Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the periodic table later?

 4

Which of the following statement(s) about the Modern Periodic Table are incorrect?

(i) The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number.


(ii) The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses.


(iii) Isotopes are placed in adjoining group (s) in the Periodic Table.


(iv) The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic number.

 5

Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period?