What is the effective nuclear charge of the following?
F-
Na+
I know that for F- it is 9-7=2
and for Na+ it is 11-2=9, but what about the charges??
I don't understand what effect do the charges make?
If 9-7 then isn't it just simply F and not F-? Similarly, if 11-2 then isn't it just simply Na and not Na+??
I think you are confused with the definition. Here is a site that gives you the effective nuclear charge for Na^+ and F^-.
Zeff = #protons -#inner electrons = ?
For Na^+ that is 11-2 = 9+.
For F^- that is 9- 2 = 7+.
https://www.google.com/search?q=effective+nuclear+charge&ie=utf-8&oe=utf-8
The effective nuclear charge refers to the net positive charge felt by an electron in an atom's outermost energy level or valence shell. To calculate the effective nuclear charge, you need to consider the atomic number and the number of inner shell electrons shielding the valence electrons from the positively charged nucleus.
In the case of F-, the atomic number is 9, but since it has a negative charge of -1, it gained an extra electron. So, the effective nuclear charge would be the atomic number (9) minus the total number of inner shell electrons. In this case, the inner shell electrons would be 7 because there are 2 electrons in the 1s orbital and 5 electrons in the 2s and 2p orbitals. Therefore, the effective nuclear charge for F- would be 9 - 7 = 2.
Similarly, for Na+, the atomic number is 11, but since it has a positive charge of +1, it lost one electron. So, again, you subtract the total number of inner shell electrons (2) from the atomic number to find the effective nuclear charge. Hence, the effective nuclear charge for Na+ would be 11 - 2 = 9.
The charges on the ions (F- and Na+) are important because they indicate the number of electrons gained or lost by the atoms. These charges determine the overall charge of the ion. The ion's charge affects the number of electrons and, consequently, the effective nuclear charge.
So, even though the effective nuclear charge for F- is 2 and Na+ is 9, it is still important to consider the charges because they indicate the gain or loss of electrons, which impact the overall behavior and reactivity of the atoms.