Periodic table history

In the modern periodic table elements are arranged by:

• atomic mass
• atomic number
• valence electrons
• number of isotopes

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

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.

• Stevie Wonder
• Sasha Vujacic
• Dmitri Mendeleev
• James Mosely

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

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

• reactivity
• boiling points
• physical properties only 
•  chemical & physical properties

The periodic table is organized by the number of ______ in each element's nucleus

• neutrons
• protons
• electrons
• atoms

Tags

NGSS.HS-PS1-8

1. Who first grouped elements in families (similar chemical and physical properties)?

• Newlands

• Mendeleev

• Dobereiner

• Moseley

Which scientist arranged the 60 known elements in columns of increasing atomic mass so that each column contained seven elements?

• Newlands

• Meyer

• Mendeleev

• Moseley