Use Equation 7.1 and assuming that core electrons contribute 1.00 and valence electrons contribute nothing to the screening constant, S, calculate Zeff} for these two ions. Express your answers as integers. Enter your answers numerically separated by a comma.
Zeff Cl-, Zeff K+
We need to know what equation 7.1 is don't we?
7,9
To calculate the effective nuclear charge (Zeff) for Cl- and K+ ions, we need to use Equation 7.1 and assume that core electrons contribute 1.00 to the screening constant (S) and valence electrons contribute nothing.
Equation 7.1 is given as:
Zeff = Z - S
For Cl-, chlorine ion with a charge of -1, the atomic number (Z) is 17. Since it has gained one electron to form the ion, the number of core electrons remains the same, which is the same as in the neutral atom of chlorine (1s22s22p6). Therefore, the number of core electrons contributing to the screening constant (S) is 10. For valence electrons, we assume that they contribute nothing, so the valence electrons for Cl- is 7.
Applying the equation:
Zeff(Cl-) = 17 - (10 + 0) = 17 - 10 = 7
Therefore, Zeff for Cl- is 7.
For K+, potassium ion with a charge of +1, the atomic number (Z) is 19. Since it has lost one electron to form the ion, the number of core electrons remains the same, which is the same as in the neutral atom of potassium (1s22s22p63s23p64s1). Therefore, the number of core electrons contributing to the screening constant (S) is 18. For valence electrons, we assume that they contribute nothing, so the valence electrons for K+ is 0.
Applying the equation:
Zeff(K+) = 19 - (18 + 0) = 19 - 18 = 1
Therefore, Zeff for K+ is 1.
So, the Zeff values are 7 for Cl- and 1 for K+.