C2 - The Periodic Table

Question 1

What is the earliest known arrangement of the periodic table?

Answer 1

John Dalton’s (1808): Organised elements in order of atomic weight with diagrams to represent each element.

Dismissed as it had no space for new elements.

Question 2

What was the arrangement of the periodic table after Dalton’s?

Answer 2

Dobereiner’s (1817): Arranged in terms of atomic weight and grouped in triads of similar properties.

Dismissed as it had no space for new elements.

Question 2

What was the arrangement of the periodic table after Dobereiner’s?

Answer 2

John Newland’s (1864): Periodic table followed the law of octaves, also in atomic weight order.

Dismissed as the law of octaves eventually didn’t apply when new elements discovered & did not leave room for new ones.