The Periodic Table

Who developed the idea of "triads" of elements with similar properties

• John Newlands

• Johann Dobereiner

• Dmitri Mendeleev

• Henry Moseley

In a chemical "triad", the masses of the three elements were related by the fact that...

• the masses of the three were the same

• their masses added up to 100%

• the average of the masses of the outer two equaled the middle one

• their masses were all unknown

Which of the following groups of elements could NOT be triad?

• Cl, Br, I

• C, N, O,

• Li, Na, K

• Ca, Ba, Sr

Who came up with the "Law of Octaves"

• Humphry Davy

• Robert Boyle

• Johann Dobereiner

• John Newlands

The "Law of Octaves" stated that..

• The properties of the elements repeated every eight when arranged by their atomic mass

• Elements could be classified in groups of three based on their mass and properties

• The properties of the elements repeated of a regular basis when arranged by their atomic number

• doubling the frequency of a tone raises its pitch by an octave

Which of these is NOT a reason that the law of octaves failed

• It didn't work for elements past calcium

• There were no allowances for undiscovered elements

• It didn't explain similar properties of any elements

• Elements with very dissimilar properties were put into the same column

The first usable modern periodic table was developed by

• Dimitri Mendeleev

• Glenn Seaborg

• John Newlands

• John Dalton

Why was Henry Moseley responsible for solving the mystery of the anomalous elements on the periodic table?

• He corrected the mass of those elements

• He corrected the properties of those elements

• He discovered the electron

• He discovered the atomic number

The periodic table is organised by the number of _ in each element's nucleus

• neutrons

• protons

• electrons

• electrons + neutrons

what property did Menedleev use to organise his periodic table

• atomic number

• atomic mass

• chemical properties