4.1 The Development of the Periodic Table of Elements

Question 1

Antoine Lavosier, French chemist

Answer 1

the first scientist who started the classification of elements into the group based on their characteristics.

Question 2

Johann W. Doberiener, German chemist

Answer 2

1. Classified elements with similar chemical properties into groups named Triads.
2. Each Triad has 3 elements only
3. The relative atomic mass of the middle element in each triad is roughly similar to the average of relative atomic mass of the other 2 elements in the triad.

Question 3

John Newlands, British chemist

Answer 3

Arranged 56 elements in ascending order of RAM. Also known as Law of Octave.

Question 4

Lothar Meyer, German chemist

Answer 4

1. Plotted a graph of atomic volume against atomic mass,
2. Elements with the same chemical properties are arranged at the equivalent positions on the curve.

Question 5

Dmitri Mendeleev, Russian chemist

Answer 5

1. Classified the elements with similar chemical properties into the same vertical column named group.
2. Exchanged the position of nickel with cobalt and iodine with tellurium so that the elements with similar chemical properties were classified in the same group.

Question 6

Henry Moseley, British chemist

Answer 6

Found out that the proton number of an element.