Electron Affinity and Ionization Energy

The video tutorial reviews ionization energy using lithium, explaining how energy is required to remove an electron. It then introduces electron affinity, describing how energy is released when an electron is added to a neutral atom, using lithium as an example. The tutorial compares ionization energy and electron affinity, highlighting the differences in energy requirements. It explores electron affinity in neon, explaining why noble gases have low affinity due to electron shielding. Finally, it discusses trends and exceptions in electron affinity across the periodic table, noting the influence of effective nuclear charge.

What is the charge of a lithium ion after losing its outermost electron?

• Positive three

• Neutral

• Positive one

• Negative one

Why does it take energy to remove an electron from a neutral atom?

• Because electrons are repelled by the nucleus

• Because electrons are attracted to the nucleus

• Because electrons are neutral

• Because electrons are positively charged

What happens to energy when an electron is added to a neutral lithium atom?

• Energy is absorbed

• Energy is released

• Energy remains constant

• Energy is destroyed

What is the electron affinity value for adding an electron to a neutral lithium atom?

• 0 KJ per mole

• -30 KJ per mole

• -60 KJ per mole

• +60 KJ per mole

Why does neon have no affinity for an extra electron?

• Because it has a full outer shell

• Because it has a positive charge

• Because it has a negative charge

• Because it is a metal

What is the effective nuclear charge experienced by an added electron in neon?

• 5

• 0

• 20

• 10

Which element in the second period has the highest electron affinity?

• Carbon

• Fluorine

• Boron

• Oxygen

What is the electron affinity value for beryllium?

• Undefined

• Positive

• Negative

• Zero

Why does nitrogen not follow the general trend in electron affinity?

• Because it has a high atomic number

• Because it has a full outer shell

• Because added electrons are repelled by existing electrons

• Because it is a noble gas

What makes electron affinity more complex than ionization energy?

• It has a clear trend

• It is always positive

• It is easier to measure

• It has many exceptions