Electron Affinity and Related Concepts

The video explains electron affinity, the energy change when an electron is added to a gaseous atom. It contrasts with ionization energy and discusses trends across the periodic table, noting exceptions. Group trends are highlighted, with halogens being highly exothermic. The video also covers energy levels, electron configurations, and factors like nuclear charge affecting electron affinity. It concludes with a method to rank elements by electron affinity.

What is electron affinity?

• The energy required to add a proton to a gaseous atom.

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

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

• The energy change when a neutron is added to a gaseous atom.

Which element releases the most energy upon gaining an electron?

• Beryllium

• Fluorine

• Neon

• Lithium

As you move down a group in the periodic table, how does electron affinity generally change?

• It becomes less exothermic.

• It remains constant.

• It becomes more exothermic.

• It becomes more endothermic.

Which group is the most exothermic when gaining an electron?

• Group 7

• Group 6

• Group 4

• Group 1

Why are alkaline earth metals generally endothermic?

• They have a full outer shell.

• They have a low atomic size.

• They require energy to place an electron in a higher energy level.

• They have a high nuclear charge.

What is the electron configuration of neon that makes it endothermic?

• 1s2 2s2 2p4

• 1s2 2s2 2p6

• 1s2 2s2 2p5

• 1s2 2s2 2p3

Why does fluorine have a high electron affinity?

• It has a low nuclear charge.

• It has a high nuclear charge and small atomic size.

• It has a large atomic size.

• It has a full outer shell.

Which element is endothermic when gaining an electron?

• Carbon

• Fluorine

• Nitrogen

• Oxygen

In the ranking of elements by electron affinity, which group is generally more exothermic than group 5?

• Group 1

• Group 4

• Group 2

• Group 8

Which element would release the most energy when an electron is added: chlorine, sulfur, silicon, sodium, or magnesium?

• Chlorine

• Sulfur

• Magnesium

• Silicon