10. Periodic Properties of the Elements

Periodic Trend: Effective Nuclear Charge

effective nuclear charge and electronegativity - vertical periodic table trend

Which will experience the greater effect nuclear charge,
the electrons in the n = 2 shell in F or the n = 2 shell in B?
Which will be closer to the nucleus?

Arrange the following atoms in order of increasing effective
nuclear charge experienced by the electrons in the n = 2
shell: Be, Br, Na, P, Se.

Effective Nuclear Charge - Chemistry Tutorial

(a) From the data in Table 8.2, calculate the effective charges
on the H atom of the HBr molecule in units of the
electronic charge, e. <img src="https://lightcat-files.s3.amazonaws.com/problem_images/bcf7d2c3d76affca-1660838913049.jpg" alt="" />

In which orbital does an electron in a sulfur atom experience the greatest shielding?

Which of the following statements about effective nuclear
charge for the outermost valence electron of an atom is incorrect?
(i) The effective nuclear charge can be thought of as the
true nuclear charge minus a screening constant due to the other
electrons in the atom. (ii) Effective nuclear charge increases
going left to right across a row of the periodic table. (iii) Valence
electrons screen the nuclear charge more effectively than do
core electrons. (iv) The effective nuclear charge shows a sudden
decrease when we go from the end of one row to the beginning
of the next row of the periodic table. (v) The change in effective
nuclear charge going down a column of the periodic table is
generally less than that going across a row of the periodic table

(b) Repeat these calculations using Slater’s rules.

Which experience a greater effective nuclear charge: the valence 
electrons in beryllium or the valence electrons in nitrogen? 
Why?

Periodic Trend: Effective Nuclear Charge Example 1

How does electron shielding in multielectron atoms give rise to energy differences among 3s, 3p, and 3d orbitals?

One method for calculating Zeff is to use the equation <img src="https://lightcat-files.s3.amazonaws.com/problem_images/a929816786d2026a-1669928316532.jpg" alt="" />
where E is the energy necessary to remove an electron from an atom and n is the principal quantum number of the elec-tron. Use this equation to calculate Zeff values for the highest-energy electrons in potassium (E = 418.8 kJ/mol) and krypton (E = 1350.7 kJ/mol).

calculating effective nuclear charge

Moving towards the top right corner of the Periodic Table causes effective nuclear charge to increase.

Using Slater’s Rules calculate the effective nuclear charge of the 4d orbital electron in iodine.

If core electrons completely shielded valence electrons from 
nuclear charge (i.e., if each core electron reduced nuclear charge 
by 1 unit) and if valence electrons did not shield one another 
from nuclear charge at all, what would be the effective nuclear 
charge experienced by the valence electrons of each atom? 
a. K

(a) From the data in Table 8.2, calculate the effective charges
on the Br atom of the HBr molecule in units of the
electronic charge, e.

In Section 3.6, we estimated the effective nuclear charge on
beryllium’s valence electrons to be slightly greater than 2+. What
would a similar treatment predict for the effective nuclear charge
on boron’s valence electrons? Would you expect the effective
nuclear charge to be different for boron’s 2s electrons compared
to its 2p electron? In what way? (Hint: Consider the shape of the
2p orbital compared to that of the 2s orbital.)

Detailed calculations show that the value of Zeff for the 
outermost electrons in Na and K atoms is 2.51+ and 3.49+, 
respectively. 
(e) Predict Zeff for the outermost electrons in the Rb atom 
based on the calculations for Na and K.

Periodic Trend: Effective Nuclear Charge Example 2

What is the identity of an element when the effective nuclear charge of its valence electrons is 18 while its shielding constant is 5?

Among the elements N, O, P, and S, which element or elements
have the smallest effect nuclear charge if we use Equation
7.1 to calculate Zeff? Which element or elements have
the largest effective nuclear charge?

Why is energy usually released when an electron is added to a neutral atom but absorbed when an electron is removed from a neutral atom?

Consider the isoelectronic ions F- and Na+. (b) Using Equation 7.1 and assuming that core electrons
contribute 1.00 and valence electrons contribute 0.00
to the screening constant, S, calculate Zeff for the 2p electrons
in both ions.

For a multielectron atom, a 3s orbital lies lower in energy than a 3p orbital because (LO 5.16)
(a) a 3p orbital has more nodal surfaces than a 3s orbital. 
(b) an electron in a 3p orbital has a higher probability of being closer to the nucleus than an electron in a 3s orbital.
(c) inner electrons shield electrons in a 3p orbital more effec-tively than electrons in a 3s orbital. 
(d) the energy of the electron can be spread between three 3p orbitals instead of only one 3s orbital.

Effective Nuclear Charge

Periodic Trend: Effective Nuclear Charge Example 3

Shielding Effect and Effective Nuclear Charge

Higher the Effective Nuclear Charge (ZEff), greater the attractive force, which results in electrons being pulled closer to the nucleus.Higher the Shielding Constant (S), greater the repulsive force between valence and inner core electrons, which results in valence electrons pushed away from the nucleus.

Detailed calculations show that the value of Zeff for the outermost 
electrons in Si and Cl atoms is 4.29+ and 6.12+, respectively. 
(a) What value do you estimate for Zeff experienced by 
the outermost electron in both Si and Cl by assuming core 
electrons contribute 1.00 and valence electrons contribute 
0.00 to the screening constant?

If core electrons completely shielded valence electrons from 
nuclear charge (i.e., if each core electron reduced nuclear charge 
by 1 unit) and if valence electrons did not shield one another 
from nuclear charge at all, what would be the effective nuclear 
charge experienced by the valence electrons of each atom? 
b. Ca

Nuclear Charge and Effective Nuclear Charge

If core electrons completely shielded valence electrons from 
nuclear charge (i.e., if each core electron reduced nuclear charge 
by 1 unit) and if valence electrons did not shield one another 
from nuclear charge at all, what would be the effective nuclear 
charge experienced by the valence electrons of each atom? 
c. O

(a) If the core electrons were totally effective at screening
the valence electrons and the valence electrons provided
no screening for each other, what would be the effective
nuclear charge acting on the 3s and 3p valence electrons
in P?

Order the electrons in the following orbitals according to their shielding ability: 4s, 4d, 4f.

Arrange the atoms according to decreasing effective nuclear 
charge experienced by their valence electrons: S, Mg, Al, Si.

Figure 7.4 shows the radial probability distribution functions
for the 2s orbitals and 2p orbitals. (b) How would you modify Slater’s rules to adjust for the difference in electronic penetration of the nucleus for the 2s and 2p orbitals?<img src="https://lightcat-files.s3.amazonaws.com/problem_images/0df150096e2fc794-1660841083898.jpg" alt="" />

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1. Intro to General Chemistry

2. Atoms & Elements

3. Chemical Reactions

4. BONUS: Lab Techniques and Procedures

5. BONUS: Mathematical Operations and Functions

6. Chemical Quantities & Aqueous Reactions

7. Gases

8. Thermochemistry

9. Quantum Mechanics

11. Bonding & Molecular Structure

12. Molecular Shapes & Valence Bond Theory

13. Liquids, Solids & Intermolecular Forces

14. Solutions

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

Periodic Trend: Cumulative

Periodic Trends are patterns present in the periodic table based on an element's size and electron distribution.&nbsp;

Periodic Trend: Ionic Radius

Ionic Radius is the distance between an ion's nucleus and its most outer occupied electron shell.&nbsp;

The Electron Configuration

The electron configuration of an element is the distribution of its electrons within atomic orbitals.&nbsp;

The Electron Configuration: Ions

The Electron Configuration of Ions involves either adding or removing electrons from a given orbital of an element.

Periodic Trend: Successive Ionization Energies

Successive Ionization Energies deals with the removal of multiple electrons from a gaseous atom or ion through multiple steps.

Periodic Trend: Atomic Radius

The atomic radius of an element is the distance from its nucleus to its outer electron shell.

Valence Electrons of Elements

The Valence Electrons represent the outer shell electrons of an element or ion.&nbsp;

Effective Nuclear Charge (Zeff) measures the force exerted onto an electron by the nucleus.&nbsp;

Periodic Trend: Ionization Energy

Ionization Energy is the energy absorbed&nbsp;in order to remove an electron from a gaseous atom or ion.&nbsp;

Periodic Trend: Metallic Character

Metallic Character&nbsp;deals with how easily an electron can be removed from an element.&nbsp;

Paramagnetism and Diamagnetism

Paramagnetism&nbsp;and&nbsp;Diamagnetism deal with the presence of electrons that are either unpaired or paired in an orbital.

Periodic Trend: Electron Affinity

Electron Affinity is the energy released from the addition of an electron to a gaseous atom or ion.&nbsp;

The Electron Configuration: Quantum Numbers

The Quantum Numbers ultimately can be used to determine the precise location of an electron.&nbsp;

Periodic Trend: Electronegativity

Electronegativity is an element's ability to attract electrons.

The Electron Configurations: Exceptions

Most Electron Configuration Exceptions are the result of elements drive to obtain half filled or totally filled d orbitals.&nbsp;

The Electron Configuration: Condensed

Condensed Electron Configurations are a faster method in determining the configuration of elements and ions.&nbsp;