History of the Periodic Table

Why were there blank spaces left in Mendeleev's periodic table?

• He didn't know what to put there.

• Undiscovered elements not yet known.

• Multiple elements could have fit

• He forgot to add the elements in.

Used the law of triads to make a list of elements

• Mendeleev

• Dobereiner

• Mosely

In the modern periodic table elements are arranged by:

• atomic mass

• atomic number

• valence electrons

• number of isotopes

Who arranged the periodic table by increasing atomic number?

• Mendeleev

• Rutherford

• Bohr

• Mosely

_______________ developed the first periodic table and arranged the elements in order of increasing atomic mass.

• Chadwick

• Rutherford

• Dmitri Mendeleev

• James Mosely

Which property did Mendeleev use to order his periodic table?

• Shielding effect

• Electronegativity

• Atomic Weight

• Metallic Character

What was Dmitri Mendeleev's greatest contribution to the history of the periodic table?

• He arranged all of the known elements by their atomic number

• He realised that there was a pattern of reactivity which repeated every 8 elements

• He predicted the existence (and properties) of new elements

• He identified the "law of triads" which became the groups

Who arranged the first periodic table.

• Mosely

• Einstein

• Mendeleev

• Bohr

Mendeleev classified elements based on not only atomic mass but what else?

• reactivity

• boiling points

• physical properties only

• chemical & physical properties

Why were there blank spaces left in Mendeleev's periodic table?

• He didn't know what to put there.

• Undiscovered elements not yet known.

• Multiple elements could have fit

• He forgot to add the elements in.