Periodic Table Trends and Properties

The video covers five key topics for the chemistry Regents exam related to the periodic table. It discusses element classifications, phases at room temperature, the significance of atomic numbers, valence electrons, and periodic trends. Additionally, it explains allotropes, which are different forms of the same element with distinct structures and properties. The video emphasizes the importance of understanding these concepts for the exam.

Which of the following elements is classified as a metalloid?

• Mercury

• Helium

• Silicon

• Oxygen

What is the only liquid metal at room temperature?

• Bromine

• Mercury

• Gallium

• Cesium

How are elements arranged on the periodic table?

• By atomic mass

• By reactivity

• By density

• By atomic number

What determines the chemical properties of elements in the same column of the periodic table?

• Number of valence electrons

• Atomic mass

• Number of neutrons

• Number of protons

How many valence electrons do elements in group 16 have?

• 4

• 5

• 6

• 7

Which trend increases as you move from left to right across a period?

• Metallic character

• Number of protons

• Atomic radius

• Electronegativity

What is the trend for atomic radius as you move down a group in the periodic table?

• Fluctuates

• Remains the same

• Decreases

• Increases

Which of the following is an example of an allotrope of carbon?

• Carbon monoxide

• Graphite

• Methane

• Carbon dioxide

What is the difference between O2 and O3 in terms of their structure?

• O2 is a metal, O3 is a nonmetal

• O2 has two oxygen atoms, O3 has three

• O2 is a gas, O3 is a solid

• O2 is a liquid, O3 is a gas

What term describes different structural forms of the same element?

• Ions

• Isotopes

• Allotropes

• Compounds