Early Attempts At Classification of Elements | Periodic Classification of Elements | Assessment | English | Grade 10

The scientist who gave the "Law of Octaves" in the early classification of elements is ______________ .

• Newlands

• Mendeleev

• Dobereiner

• None of the above

Answer explanation

The scientist who gave the "Law of Octaves" in the early classification of elements is John Newlands.

The scientist who gave the "Law of Triads" in the early classification of elements is ______________ .

• Newlands

• Dobereiner

• Mendeleev

• None of the above

Answer explanation

The scientist who gave the "Law of Triads" in the early classification of elements is Dobereiner.

One example of a Dobereiner’s triad is ___________ .

• Li,Na,K

• Li, Mg, Na

• Li, He, P

• P, As, Cl

Answer explanation

Li, Na and K follow Dobereiner triad.

According to Newlands’ classification of elements, the properties of Sodium are similar to those of Lithium because sodium is the _________ element starting from lithium.

• 4

• 6

• 8

• 10

Answer explanation

According to Newlands’ classification of elements, the properties of sodium are similar to those of lithium because sodium is the eighth element starting from lithium.

Limitations of Newlands’ law of octaves is/are _____________ .

• It failed to arrange all the then known elements in the form of triads of elements having similar chemical properties

• Newlands’ law of octaves was applicable to the classification of elements up to calcium only

• Atomic masses weren't equal

• All of the above

Answer explanation

Newlands’ law of octaves was applicable to the classification of elements up to calcium only. After calcium every eighth element did not possess properties similar to that of the first.