Zeff
Effective nuclear charge
What is Zeff?
Decrease in size
What happens to atoms along a period?
K > Na > Li
Arrange the first three elements of Group 1 in decreasing order of atomic size
Atomic Number (Z) - Shielding Constant (S)
How can Zeff be calculated?
An increase
What happens to the nuclear charges of atoms along a period?
Increase in number
What happens to shells of atoms down a group?
For a shielding constant of 10, 7
What is the shielding constant of chlorine?
Noble Gases
Which group of the Modern Periodic Table is an exception to the rule of atomic size across a period?
Increase in size
What happens to atoms down a group?
For a shielding constant of 1.7, 1.3
What is the Zeff of lithium?
Electrons are pulled closer to the nucleus
Why does atomic size decrease across a period?
New shells are added
Why does atomic size increase down a group?
for a shielding constant of 3.45, 4.55
What is the Zeff of oxygen?
Strong inter-electronic repulsion in the valence shell
Why are noble gases an exception to the rule of atomic size across a period?
Addition of shells counteracts nuclear charge
Why doesn't atomic size decrease down a group?