Electron Affinity Concepts and Trends

The video tutorial by MSJ Chem explains electron affinity, focusing on the energy changes when electrons are added to gaseous atoms. The first electron affinity is exothermic, while the second is endothermic due to repulsion in negative ions. Factors like atomic radius and electron shielding influence these values, with trends observed across groups and periods in the periodic table.

What is the first electron affinity?

• The energy required to remove an electron from a gaseous atom

• The energy released when an electron is added to a gaseous atom

• The energy required to add an electron to a solid atom

• The energy released when an electron is removed from a gaseous ion

Why are first electron affinity values always negative?

• Because they are endothermic

• Because they involve energy absorption

• Because they involve energy loss

• Because they are exothermic

What does the second electron affinity involve?

• Adding an electron to a neutral atom

• Removing an electron from a negative ion

• Adding an electron to a negative ion

• Removing an electron from a neutral atom

Why are second electron affinity values positive?

• Due to energy release

• Due to electron attraction

• Due to extra repulsion

• Due to energy absorption

How does atomic radius affect first electron affinity?

• Larger atomic radius increases energy release

• Larger atomic radius decreases energy release

• Smaller atomic radius decreases energy release

• Atomic radius has no effect

What trend is observed in Group 1 regarding first electron affinity?

• It fluctuates randomly

• It increases down the group

• It remains constant

• It decreases down the group

In Group 16, how does the first electron affinity of oxygen compare to sulfur?

• Both have the same electron affinity

• Sulfur is more exothermic than oxygen

• Oxygen is endothermic while sulfur is exothermic

• Oxygen is more exothermic than sulfur

What is the trend in first electron affinity from chlorine to astatine in Group 17?

• It fluctuates

• It remains the same

• It decreases

• It increases

How does the first electron affinity trend across a period starting with Group 13?

• It tends to decrease

• It tends to increase

• It remains constant

• It fluctuates

What is a common exception to the trend of increasing first electron affinity across a period?

• Group 13 elements

• Group 18 elements

• Group 2 elements

• Group 1 elements