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

Question

Accepted Answer

Hey everyone in this example, we need to identify which of the below statements are false statements. So looking at statement one, it says that the effective nuclear charge is the force exerted by the nucleus onto an electron. And we would actually agree with the statement as a true statement because it correctly defines effective nuclear charge. Moving on to statement B, it says that the core electrons screen the nuclear charge more effectively than valence electrons. We would also recognize that this is a true statement. There's no corrections here needed to be made. So, moving on to statement, see it says that electrons that are further away from the nucleus experience a lower effective nuclear charge. We would also agree with this as a true statement. We can also recall that atoms that have a lower value for their atomic number would therefore have a lower value for their effective nuclear charge. Moving on to statement D, it says that the effective nuclear charge increases from left to right in the periodic table. And this would definitely be a correct recollection of our trend for effective nuclear charge on our periodic table. So, we would agree with this statement. And lastly, we have statement E which says that the change in effective nuclear charge increases down a period in the periodic table. We want to correct this statement here. So that it says decreases down the periodic table. And so this would be a false statement, which means that this is the only correct choice to choose for the false statement given in this example. So this is our final answer. If you have any questions, please leave them down below. Otherwise, I'll see everyone in the next practice video.

Verified Solution

Key Concepts

Effective Nuclear Charge (Z_eff)

Shielding Effect

Periodic Trends