How The Elements Are Laid Out In The Periodic Table

The video explains the evolution of the periodic table from Mendeleev's arrangement by atomic mass to the modern arrangement by atomic number. It highlights the advantages of the modern table, such as resolving placement issues like iodine and tellurium. The video also discusses the creation of new, highly radioactive elements and how their properties can be predicted based on their position in the table. Finally, it describes the basic division of the periodic table into metals and nonmetals.

What is the main difference between Mendeleev's periodic table and the modern periodic table?

• Both tables are arranged by atomic number.

• Mendeleev's table is arranged by atomic mass, while the modern table is by atomic number.

• Mendeleev's table is arranged by atomic number, while the modern table is by atomic mass.

• Both tables are arranged by atomic mass.

Why did Mendeleev place iodine before tellurium in his periodic table?

• Iodine has similar properties to fluorine, chlorine, and bromine.

• Iodine has a higher atomic number than tellurium.

• Iodine has a higher atomic mass than tellurium.

• Iodine is more reactive than tellurium.

How many elements are currently in the modern periodic table?

• Around 110

• Around 100

• Around 120

• Around 115

What is a characteristic of the new elements being created by scientists?

• They are stable and long-lasting.

• They are highly radioactive and decay rapidly.

• They have no predictable properties.

• They are found naturally in the environment.

How is the periodic table divided in its most basic form?

• Into gases and liquids

• Into metals and nonmetals

• Into solids and gases

• Into elements and compounds