Atomic Radius Trends and Calculations in the Periodic Table

The video tutorial explains the concept of atomic radius, how it is calculated, and the trends observed in the periodic table. It covers the decrease in atomic radius across a period due to increasing nuclear charge and the increase down a group due to additional energy levels. The tutorial also includes problem-solving examples comparing atomic radii of various elements.

How is the atomic radius of an atom like bromine determined?

• By calculating the mass of the atom

• By measuring the diameter of the atom

• By halving the distance between the nuclei of two atoms in a molecule

• By adding the atomic numbers of the atoms

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

• It increases

• It remains constant

• It decreases

• It fluctuates randomly

Why does the atomic radius decrease across a period?

• Because the effective nuclear charge increases

• Because the nuclear charge decreases

• Because the number of energy levels decreases

• Because the number of neutrons increases

What is the effective nuclear charge felt by the valence electron in lithium?

• +0

• +2

• +1

• +3

What causes the atomic radius to increase as you move down a group?

• Increase in the number of neutrons

• Decrease in the number of protons

• Increase in the number of energy levels

• Decrease in nuclear charge

Which element is larger: sodium or lithium?

• It depends on the isotope

• Sodium

• Lithium

• They are the same size

Which element is larger: calcium or magnesium?

• It depends on the isotope

• They are the same size

• Magnesium

• Calcium

Which element is larger: silicon or phosphorus?

• Silicon

• Phosphorus

• They are the same size

• It depends on the isotope

Which element is larger: strontium or sulfur?

• Sulfur

• It depends on the isotope

• Strontium

• They are the same size

Rank the following elements in order of increasing atomic size: Neon, Chlorine, Selenium, Tin, Cesium.

• Neon, Chlorine, Selenium, Tin, Cesium

• Tin, Cesium, Neon, Chlorine, Selenium

• Selenium, Neon, Cesium, Tin, Chlorine

• Cesium, Tin, Selenium, Chlorine, Neon