Periodic Trends: Electronegativity and Electron Affinity

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What is electronegativity?

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond.

How does electronegativity change across a period?

Electronegativity increases across a period as effective nuclear charge increases.

How does electronegativity change down a group?

Electronegativity decreases down a group due to increased distance from the nucleus.

Why is fluorine the most electronegative element?

Fluorine has a high effective nuclear charge and a small atomic radius, allowing it to attract electrons strongly.

What is electron affinity?

Electron affinity is the energy change that occurs when an atom gains an electron.

How does electron affinity change across a period?

Electron affinity generally becomes more negative across a period as atoms more readily gain electrons.

How does electron affinity change down a group?

Electron affinity becomes less negative down a group as added electrons are further from the nucleus.

Why do noble gases have low electron affinities?

Noble gases have full valence shells, making them stable and less likely to gain electrons.

Which area of the periodic table tends to have higher electron affinities?

Nonmetals, particularly halogens, have higher electron affinities as they readily gain electrons to achieve noble gas configuration.

How does atomic number affect electronegativity?

Higher atomic numbers usually increase electronegativity, especially across a period, due to increased nuclear charge.

What trend is observed for electronegativity in transition metals?

Transition metals often have similar electronegativities within their groups due to similar atomic structures.

Why do alkali metals have low electronegativities?

Alkali metals have low electronegativities because they tend to lose electrons easily to form positive ions.

What is the connection between electronegativity and chemical bonding?

Differences in electronegativity between atoms determine the type of bond (ionic, polar covalent, or nonpolar covalent) formed.

How does electronegativity affect molecule polarity?

Greater differences in electronegativity between atoms in a molecule create polar bonds, resulting in polar molecules.

Why is electron affinity important in forming anions?

Electron affinity indicates how easily an atom can gain electrons to form anions, influencing their chemical behavior.