This video covers periodic trends, focusing on atomic and ionic sizes. It explains how effective nuclear charge and energy levels influence atomic radius, which decreases across a period and increases down a group. The video also discusses ionic size, noting that cations are smaller and anions are larger than their neutral atoms. It highlights the role of nuclear charge in isoelectronic series, where ions with the same number of electrons vary in size based on their charge.

What are the two main generalizations used to justify periodic trends?

• Atomic mass and increased distance/shielding

• Effective nuclear charge and increased distance/shielding

• Effective nuclear charge and electron configuration

• Electron configuration and atomic mass

How is the bonding atomic radius defined?

• The distance from the nucleus to the outer edge of the electron cloud

• Half the distance between two bonded nuclei

• The distance between two non-bonded atoms

• The distance from the nucleus to the valence electrons

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

• It decreases

• It increases

• It fluctuates

• It remains the same

Why does the atomic radius decrease across a period?

• Because the number of energy levels decreases

• Because the effective nuclear charge decreases

• Because the effective nuclear charge increases

• Because the number of protons decreases

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

• It decreases

• It remains the same

• It increases

• It fluctuates

What happens to the size of cations compared to their neutral atoms?

• Cations are larger

• Cations remain the same size

• Cations are smaller

• Cations fluctuate in size

Why are anions larger than their neutral atoms?

• Because they gain electrons

• Because they lose electrons

• Because they lose protons

• Because they gain protons

What is the trend in ionic radius for cations across a period?

• It increases

• It remains the same

• It fluctuates

• It decreases

In an isoelectronic series, what happens to the ionic size as nuclear charge increases?

• It fluctuates

• It remains the same

• It decreases

• It increases

Which ion in the isoelectronic series O2-, F-, Na+, Mg2+, and Al3+ has the smallest radius?

• Al3+

• O2-

• Na+

• F-