In Newlands' octaves, which of the following pairs of elements were placed in the same column along with H, F, Cl and Br?

Correct option is A

• The Correct answer is A. Co and Ni
• Newlands periodic table: Johan Newlands an English chemist has classified 56 elements into 11 groups based on the physical properties and proposed the Law of Octaves which states that every eight elements repeated its physical and chemical properties.
• Understand Newland's Octave Rule: Newland's octave rule states that when elements are arranged in order of increasing atomic weight, every eighth element has similar properties. This means that if we list elements in order of their atomic weights, the first element will have properties similar to the ninth, the second to the tenth, and so forth.
• Newlands placed cobalt and nickel in the same slot and positioned them in the same column with fluorine, chlorine and bromine that possess different properties compared to these two elements (Cobalt and Nickel).