Periodic Table

Law of Triads

• The Law of Triads describes the significance of the middle element in a group of three.
• The Law of Triads is a principle that applies only to pairs of elements.
• The Law of Triads states that all elements in a group of three are equally important.
• The Law of Triads emphasizes the importance of the first and last elements in a group of three.

Who discovered Law of Triads?

• Glenn Seaborg

• Henry Moseley

• Dmitri Mendeleev
• Johann Wolfgang Döbereiner

Who discovered Transuranium Elements?

• Glenn Seaborg

• Henry Moseley

• Dmitri Mendeleev
• Johann Wolfgang Döbereiner

Who discovered Law of Octaves?

• John Newlands
• Henry Moseley
• Lothar Meyer
• Dmitri Mendeleev

Who discovered the Periodic Table?

• Dmitri Mendeleev
• Glenn Seaborg

• John Newlands

• Johann Wolfgang Dobereiner

Who discovered the Modern Periodic Table?

• Dmitri Mendeleev
• John Newlands

• Henry Moseley

• Johann Wolfgang Dobereiner

The average of the atomic masses of the first and third elements in a triad is approximately equal to the atomic mass of the second element in that triad.

• Periodic Table

• Transuranium Elements

• Law of Triads

• Law of Octaves

When elements are arranged by atomic mass, the eighth element’s properties are similar to that of the first.

• Periodic Table

• Transuranium Elements

• Law of Triads

• Law of Octaves

In Law of Octaves, the pattern seemed true only up until the element ----

• sodium
• iron
• gold
• calcium

Dmitri Mendeleev arranged the 60 known elements at that time using ---- atomic mass.

• increasing

• decreasing