lecture 9 notes

did:9/28, lecture date:9/17

What is effective nuclear charge?

proton charge- core e-

T or F: Atoms shrink as effective nuclear charge increases.

True

Why is the atomic radius smaller for Nitrogen?

half-filled P-subshell

What happens to the radius of d-elements?

decreases→ increases (b/c too much repulsion)

What is the atomic radius trend for groups?

increases down a group

What is the main group exception to the atomic radius group trend?

Group 13

Why is Ga smaller than Al when lower in the group?

3d electron contraction ( poor shielding)

What is ionization energy?

smallest energy required to eject electrons

Ionization energy only applies to attoms in ___ phase.

gas

Ionization energy _____ across the _____.

increases; period

Ionization energy _____ down the ____.

decreases; group

What elements have the highest ionization energy?

noble gases

Why do noble gases have the highest Ionization energy ?

they are the most stable

T or F: It is always harder to pull electrons from cations.

True

How does Ionization energy change when pulling core electrons?

It is MUCH larger

What is electron affinity?

energy to add extra electron to atom

What elements don’t want extra electrons?

noble gases, Be, Mg, N (big mighty no! to extra e-)

T or F: Fluorine has higher electron affinity than Chlorine.

False

Why does Chlorine have higher electron affinity than Flourine?

It’s bigger (easier to hold e-)

What group has the highest (most favorable) electron affinity?

halogens

Electronegativity trend is similar to which trend?

Ionization energy

Electronegativity ____ down ____ and ___ down ____.

decreases; increases, groups; periods

Atoms with ____ electronegativity ___ electrons

low;lose, high;gain

Diagnonal elements have similar _____ and _____.

electronegativities; chemical properties

Which group has the lowest electronegativity?

alkali metals

How does ionic radius change going down a group?

increases

How does the radius of a cation compare to its parent neutral atom?

its ALWAYS smaller

How does the radius of an anion compare to its parent neutral atom?

its ALWAYS larger

Are 2nd and higher electron affinities favorable (negative) or unfavorable (positive)?

unfavorable (adding more e- when already negative making it more unstable)