Mendeleev's Periodic Table Insights

The video tutorial covers the evolution of element classification methods, focusing on Mendeleev's periodic table. Mendeleev arranged elements by atomic mass and predicted properties of undiscovered elements. His periodic law states that element properties are periodic functions of atomic masses. The video also discusses the inclusion of noble gases and revisions made to the table.

Who developed the periodic table of elements during the period 1869 to 1870?

• John Newlands

• Henry Moseley

• Lothar Meyer

• Dmitri Mendeleev

What fundamental property did Mendeleev use to arrange the elements in his periodic table?

• Electronegativity

• Atomic number

• Atomic mass

• Valency

How many elements did Mendeleev arrange in his periodic table?

• 50

• 63

• 100

• 75

Which properties did Mendeleev consider after arranging elements by atomic mass?

• Magnetic properties

• Reactivity with water

• Physical and chemical properties

• Color and texture

What did Mendeleev find about elements with similar properties?

• They have the same density

• They have the same atomic number

• They repeat after a definite interval

• They are all metals

What are the vertical columns in Mendeleev's periodic table called?

• Groups

• Periods

• Blocks

• Rows

How many groups are there in Mendeleev's periodic table?

• 6

• 7

• 8

• 9

What did Mendeleev predict about the elements not yet discovered?

• They would be radioactive

• They would have similar properties to known elements

• They would not fit into the periodic table

• They would be gases

Which group was added to the periodic table after the discovery of noble gases?

• Group 1

• Zero group

• Group 8

• Group 7

What was the initial incorrect atomic mass of beryllium before it was revised?

• 9.4

• 12.01

• 14.09

• 10.5