Hi everyone, I'm having problems with effective nuclear charge. Regarding these problems.
Calculate Zeff for a valence electron in an oxygen atom.
and
Calculate Zeff for the 4s electron in a copper atom, .
and
Calculate Zeff for a 3d electron in a copper atom, Cu.
Like for the first question it was Zeff= 8-2
= +6 but it was wrong so i'm lost.
The question gave further info with regards to the formula Zeff= Z-S
where is true nuclear charge and is the amount of shielding.
In 1930, John C. Slater devised the following set of empirical rules to estimate for a designated or electron:
Write the electron configuration of the element, and group the subshells as follows: (1s), (2s, 2p), (3s, 3p), (3d), (4s, 4p), (4d), (4f ), (5s, 5p), and so on.
Electrons in groups to the right of the (, ) group contribute nothing to the shielding constant for the designated electron.
All the other electrons in the (ns,np ) group shield the designated electron to the extent of 0.35 each.
All electrons in the n-1 shell shield to the extent of 0.85 each.
All electrons in the n-2 shell, or lower, shield completely—their contributions to the shielding constant are 1.00 each.
When the designated electron is in an nd or nf group, rules (i), (ii), and (iii) remain the same but rules (iv) and (v) are replaced by the following:
Each electron in a group lying to the left of nf or nd group contributes 1.00 to the shielding constant.
These rules are a simplified generalization based on the average behavior of different types of electrons.
A) 8 - 3.45 = 4.55
B) 29 - 25.30 = 3.70
C) 29 - 21.15 = 7.85
D) (I had the same homework)
1.effective nuclear charge
2.principle quantum number
plz help :(
To calculate Zeff for a valence electron in an oxygen atom, we need to determine the values for Z (true nuclear charge) and S (amount of shielding).
Step 1: Write the electron configuration of oxygen. Oxygen has atomic number 8, so its electron configuration is 1s² 2s² 2p⁴.
Step 2: Group the subshells as mentioned in the rules. For oxygen, we have (1s), (2s, 2p).
Step 3: Determine the amount of shielding for the valence electron. In this case, it's the 2p electron.
- Electrons in groups to the right of the (2p) group contribute nothing to the shielding constant for the designated electron. So the (2s) electrons do not contribute to shielding.
- All the other electrons in the (2p) group shield the designated electron to the extent of 0.35 each.
Since the (2p) group has 4 electrons, the shielding contribution is 0.35 × 4 = 1.40.
Step 4: Calculate Zeff using the formula Zeff = Z - S. For oxygen, Z is the atomic number, which is 8. Therefore, Zeff = 8 - 1.40 = 6.60.
So, the effective nuclear charge (Zeff) for a valence electron in an oxygen atom is approximately 6.60.
Now let's move on to the second question: Calculate Zeff for the 4s electron in a copper atom (Cu).
Step 1: Write the electron configuration of copper. Copper has atomic number 29, so its electron configuration is [Ar] 3d¹⁰ 4s².
Step 2: Group the subshells as mentioned in the rules. For copper, we have (3d), (4s).
Step 3: Determine the amount of shielding for the 4s electron.
- Electrons in groups to the right of the (4s) group contribute nothing to the shielding constant for the designated electron. So the (3d) electrons do not contribute to shielding.
- All the electrons in the (3d) group shield the designated (4s) electron to the extent of 0.35 each.
Since the (3d) group has 10 electrons, the shielding contribution is 0.35 × 10 = 3.50.
Step 4: Calculate Zeff using the formula Zeff = Z - S. For copper, Z is the atomic number, which is 29. Therefore, Zeff = 29 - 3.50 = 25.50.
So, the effective nuclear charge (Zeff) for the 4s electron in a copper atom is approximately 25.50.
Lastly, let's calculate Zeff for a 3d electron in a copper atom (Cu).
Step 1: Same as before, write the electron configuration of copper: [Ar] 3d¹⁰ 4s².
Step 2: Group the subshells: (3d), (4s).
Step 3: Determine the amount of shielding for the 3d electron. It is shielded only by the (4s) electrons, which contribute 0.35 to the shielding constant each.
So, the shielding contribution is 0.35 × 2 = 0.70.
Step 4: Calculate Zeff using the formula Zeff = Z - S. For copper, Z is 29. Therefore, Zeff = 29 - 0.70 = 28.30.
So, the effective nuclear charge (Zeff) for a 3d electron in a copper atom is approximately 28.30.
Have you seen this. It is a site that essentially does what you have described for you.
http://www.chm.davidson.edu/ronutt/che115/Zeff/Zeff.htm