Periodic trends and effective nuclear charge

Click For Summary
SUMMARY

The discussion centers on the relationship between atomic radii and effective nuclear charge (Zeff) as elements are analyzed across the periodic table. It is established that atomic radii decrease from left to right due to an increase in effective nuclear charge, which is defined by the equation Zeff = Z - S. The confusion arises regarding the impact of additional valence electrons on shielding (S), which can reduce Zeff despite an increase in proton number (Z). The new valence electron contributes less to shielding than one full elementary charge, leading to a net increase in Zeff.

PREREQUISITES
  • Understanding of atomic structure and periodic trends
  • Familiarity with the concept of effective nuclear charge (Zeff)
  • Knowledge of electron shielding and its effects on atomic properties
  • Basic grasp of the periodic table and element positioning
NEXT STEPS
  • Study the concept of electron shielding in detail
  • Explore the mathematical derivation of effective nuclear charge
  • Investigate periodic trends in atomic radii across different groups and periods
  • Examine the role of additional valence electrons in determining Zeff
USEFUL FOR

Chemistry students, educators, and anyone interested in understanding atomic structure and periodic trends in the context of effective nuclear charge.

henry3369
Messages
194
Reaction score
0
My book is trying to explain why atomic radii decreases as you move toward the right side of the periodic table because the effective nuclear charge increases. I understand why an increase in effective nuclear charge results in a smaller radius, but I don't know why the effective nuclear charge would decrease with more valence electrons. If Zeff= Z-S, then an increase in valence electrons would increase shielding; thus, Zeff would be smaller with an increase in S.
 
Chemistry news on Phys.org
You increase the proton number Z by 1, but the new electron won't be completely inside so its shielding effect is less than one elementary charge.
 

Similar threads

Replies
0
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
4
Views
2K
Replies
3
Views
3K
Replies
6
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K