Properties and Classification of Elements

The video tutorial explores the periodic table, starting with its historical development by Dmitri Mendeleev, who organized elements by chemical properties and predicted unknown elements. Henry Moseley's work on atomic numbers led to a reorganization of the table. The modern periodic table is structured into periods and families, with specific groups like alkali metals and noble gases. The video also covers the properties of metals, non-metals, and metalloids, highlighting their differences and uses.

Who is credited with the creation of the modern periodic table?

• Marie Curie

• Albert Einstein

• Dimitri Mendeleev

• Henry Moseley

What was unique about Mendeleev's periodic table?

• It was the first to use chemical symbols.

• It included all known elements at the time.

• It predicted the existence of unknown elements.

• It was organized by atomic number.

What significant change did Henry Moseley make to the periodic table?

• He introduced the concept of isotopes.

• He added new elements.

• He organized it by atomic number.

• He removed non-metals.

What are the rows in the periodic table called?

• Periods

• Groups

• Blocks

• Families

Which group is known as the noble gases?

• Group 18

• Group 14

• Group 1

• Group 17

What is a characteristic property of metals?

• They are poor conductors of electricity.

• They are good conductors of heat and electricity.

• They are brittle.

• They have low melting points.

Which of the following is a property of non-metals?

• They are malleable.

• They are ductile.

• They are poor conductors of heat.

• They are shiny.

What distinguishes metalloids from metals and non-metals?

• They are all liquids.

• They are all non-reactive.

• They have properties of both metals and non-metals.

• They are all gases.

What does the stair-step line on the periodic table separate?

• Noble gases from halogens

• Metals from non-metals

• Transition metals from lanthanides

• Alkali metals from alkaline earth metals

Which element is an exception to the rule of metalloids touching the stair-step line?

• Boron

• Arsenic

• Aluminum

• Silicon