Question

What is NET NUCLEAR FORCE n Zeff....
Plzzz ans the ques by full explaination i will make it brainiliest.. plzzz guyss help me 2morrow is my xam...

Answer 1

Effective nuclear charge – the attractive
positive charge of nuclear protons acting on
valence electrons.
1. The effective nuclear charge is always
less than the total number of protons
present in a nucleus due to shielding
effect.
2. Effective nuclear charge is behind all
other periodic table tendencies.
Shielding effect – the lessening of attractive
electrostatic charge difference between
nuclear protons and valence electrons by
partially or fully filled inner shells.
1. Shielding effect increases with the
number of inner shells of electrons.
2. Electrons sharing the same shell do
not shield one another from the
attractive pull of the nucleus.
Calculating the effective nuclear charge:
An estimate of effective nuclear charge can
be obtained from Zeff = Z - S, where Zeff =
effective nuclear charge, Z = atomic number,
and, S = the screening constant. ""Consider
aluminum: [Ne]3s 3p "" Z = 13 S = 10 Zeff =
Z - S = 13 - 10 = 3+
Don’t forget that Zeff is only an estimate.
Actual shielding effect is always greater
that the screening constant S because
core electrons are much closer to the
nucleus than are valence electrons.
Trends
The periodic table tendency for effective
nuclear charge:
1. Increase across a period (due to
increasing nuclear charge with no
accompanying increase in shielding
effect).
2. Decrease down a group (although
nuclear charge increases down a
group, shielding effect more than
counters its effect).