Periodic Table History and Development Assessment

What significant contribution did Dmitri Mendeleev make to chemistry in 1869?

• He discovered the noble gases

• He published the first systematic classification of elements

• He discovered atomic numbers

• He identified radioactive elements

According to the notes, why was Mendeleev's arrangement of elements initially problematic regarding iodine and tellurium?

• They had similar properties but different masses

• They were placed in the wrong family

• To maintain similar properties in groups, tellurium (higher mass) had to be placed before iodine (lower mass)

• They were discovered after the table was published

Which scientist's discovery led to arranging elements by atomic number rather than atomic mass?

• Dmitri Mendeleev

• William Ramsay

• John William Strutt

• Henry Moseley

What is the Periodic Law's fundamental principle?

• Elements are arranged by increasing atomic mass

• Elements are arranged in groups of similar properties

• Physical and chemical properties are periodic functions of atomic numbers

• Elements are organized by electron configuration

What discovery about noble gases significantly impacted the periodic table's development?

• They were all discovered simultaneously

• Argon was the first noble gas discovered in 1894

• They were initially part of Mendeleev's table

• They were discovered before the periodic table was created

What did Moseley determine about atomic numbers?

• They were related to atomic mass

• They were equal to the nuclear charge

• They determined period length

• They indicated valence electrons

How are elements in the same period related to each other?

• They have the same number of valence electrons

• They have identical chemical properties

• They have the same number of principal energy levels

• They have the same atomic mass

What determines the length of each period in the periodic table?

• The atomic number of elements

• The number of electrons that can occupy the sublevels being filled

• The number of valence electrons

• The atomic mass of elements

How do you determine the number of valence electrons for main group elements?

• Subtract 10 from the atomic number

• Equal to the period number

• Equal to the group number (for IA-VIIIA) or group number minus 10

• Equal to the total number of electrons

What are the four blocks of the periodic table based on?

• The atomic mass of elements

• The electron sublevel being filled

• The number of valence electrons

• The atomic number sequence