11/29/22 - Electrons and Periodic Trends Flashcards
Does similar electron configuration confer similar chemical behavior?
Yes
What are inner electrons?
Those in the noble gas core plus any additional complete d-sublevels
What are outer electrons?
Those in the highest occupied energy level (all electrons at the highest n value)
Which electrons are valence electrons?
In main-group elements, they are the outer electrons
In transition elements, they are the outer electrons plus the highest d-sublevel electrons
Which electrons participate in forming bonds?
Valence
The electron configuration for F is
[He]2s^2 2p^5
How many inner electrons are there?
2 from the He
The electron configuration for F is
[He]2s^2 2p^5
How many outer electrons are there?
7 because the highest energy level is n = 2, which has 7 electrons
The electron configuration for F is
[He]2s^2 2p^5
How many valence electrons are there?
- F is a main-group element, so the outer electrons are the valence electrons
The electron configuration for Cr is
[Ar]4s^1 3d^5
How many inner electrons are there? (Ar is Z = 18)
18 from Ar
The electron configuration for Cr is
[Ar]4s^1 3d^5
How many outer electrons are there?
- The highest energy level is n=4, which has 1 electron.
The electron configuration for Cr is
[Ar]4s^1 3d^5
How many valence electrons are there?
- Cr is a transition element, so its 1 outer electron and 5 3d electrons are valence
The electron configuration for Br is
[Ar]4s^2 3d^10 4p^5
How many inner electrons are there? (Ar is Z = 18)
28, there are 18 from Ar and 10 from the complete 3d sublevel
The electron configuration for Br is
[Ar]4s^2 3d^10 4p^5
How many outer electrons are there?
- There are 7 electrons in the n=4 energy level
The electron configuration for Br is
[Ar]4s^2 3d^10 4p^5
How many valence electrons are there?
- As a main group element, the valence electrons of Br are the outer electrons
Why is the electron configuration of copper
[Ar]4s^1 3d^10 instead of 4s^2 3d^9?
Because half-filled and fully filled sublevels are more stable.
Likewise Cr is [Ar]4s^1 3d^5
Which three properties are influenced by electron configuration and effective nuclear charge?
Atom size, ionization energy, and electron affinity
As the principal quantum number (n) increases, does atom size increase or decrease?
Increase
As effective nuclear charge increases, does atom size increase or decrease?
Decrease because atoms are pulled closer
Atom size is greater:
Top or bottom of the periodic table?
Right or left?
Bottom and left
How is atomic radius found?
It is half the distance between the nearest adjacent or bonded atoms
