Atomic Radius Trends and Concepts

The video tutorial explains the concept of atomic radius, which is the distance between the nucleus and the outermost electron of an atom. It discusses how atomic radius is measured in picometers and explores periodic trends. Across a period, atomic radius decreases due to increased nuclear attraction, while down a group, it increases due to added electron shells and increased shielding effect. Examples with elements like hydrogen, sodium, lithium, carbon, oxygen, and fluorine illustrate these trends.

What is the atomic radius?

• The number of electrons in an atom

• The mass of an atom

• The number of protons in an atom

• The distance between the nucleus and the outermost electron

In which unit is atomic radius measured?

• Millimeter

• Picometer

• Nanometer

• Micrometer

What happens to the atomic radius as you move across a period from left to right?

• It increases

• It fluctuates

• It decreases

• It remains constant

Which element has the highest attraction between protons and electrons in the second period?

• Fluorine

• Lithium

• Oxygen

• Carbon

Why does the atomic radius decrease across a period?

• Because the shielding effect decreases

• Because the atomic number increases and the number of shells remains constant

• Because the atomic number decreases

• Because the number of shells increases

What is the trend of atomic radius as you move down a group?

• It decreases

• It increases

• It remains constant

• It fluctuates

What is the shielding effect?

• The decrease in atomic radius

• The repulsion between electrons in different shells

• The attraction between protons and electrons

• The increase in atomic number

Why is the atomic radius of sodium larger than that of lithium?

• Because sodium has more shells and a greater shielding effect

• Because sodium has fewer protons

• Because sodium has fewer electrons

• Because sodium has a smaller atomic number

What happens to the number of shells as you move down a group?

• It decreases

• It increases

• It remains constant

• It fluctuates

What is the overall trend of atomic radius in the periodic table?

• Fluctuates randomly across a period and down a group

• Remains constant across a period and down a group

• Increases across a period and decreases down a group

• Decreases across a period and increases down a group