<Dd> ⟨ r ⟩ Z (\ displaystyle \ langle r \ rangle _ (Z)) is the mean radius of the orbital for an electron configuration with nuclear charge Z . </Dd> <P> Updated values of screening constants were provided by Clementi et al . </P> <Table> Effective Nuclear Charges <Tr> <Td> </Td> <Td> </Td> <Td_colspan="16"> </Td> <Td> He </Td> </Tr> <Tr> <Td> Z </Td> <Td> </Td> <Td_colspan="16"> </Td> <Td> </Td> </Tr> <Tr> <Td> 1s </Td> <Td> 1.000 </Td> <Td_colspan="16"> </Td> <Td> 1.688 </Td> </Tr> <Tr> <Td> </Td> <Td> Li </Td> <Td> Be </Td> <Td_colspan="10"> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Ne </Td> </Tr> <Tr> <Td> Z </Td> <Td> </Td> <Td> </Td> <Td_colspan="10"> </Td> <Td> 5 </Td> <Td> 6 </Td> <Td> 7 </Td> <Td> 8 </Td> <Td> 9 </Td> <Td> 10 </Td> </Tr> <Tr> <Td> 1s </Td> <Td> 2.691 </Td> <Td> 3.685 </Td> <Td_colspan="10"> </Td> <Td> 4.680 </Td> <Td> 5.673 </Td> <Td> 6.665 </Td> <Td> 7.658 </Td> <Td> 8.650 </Td> <Td> 9.642 </Td> </Tr> <Tr> <Td> 2s </Td> <Td> 1.279 </Td> <Td> 1.912 </Td> <Td_colspan="10"> </Td> <Td> 2.576 </Td> <Td> 3.217 </Td> <Td> 3.847 </Td> <Td> 4.492 </Td> <Td> 5.128 </Td> <Td> 5.758 </Td> </Tr> <Tr> <Td> 2p </Td> <Td> </Td> <Td> </Td> <Td_colspan="10"> </Td> <Td> 2.421 </Td> <Td> 3.136 </Td> <Td> 3.834 </Td> <Td> 4.453 </Td> <Td> 5.100 </Td> <Td> 5.758 </Td> </Tr> <Tr> <Td> </Td> <Td> Na </Td> <Td> Mg </Td> <Td_colspan="10"> </Td> <Td> Al </Td> <Td> Si </Td> <Td> </Td> <Td> </Td> <Td> Cl </Td> <Td> Ar </Td> </Tr> <Tr> <Td> Z </Td> <Td> 11 </Td> <Td> 12 </Td> <Td_colspan="10"> </Td> <Td> 13 </Td> <Td> 14 </Td> <Td> 15 </Td> <Td> 16 </Td> <Td> 17 </Td> <Td> 18 </Td> </Tr> <Tr> <Td> 1s </Td> <Td> 10.626 </Td> <Td> 11.609 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 12.591 </Td> <Td> 13.575 </Td> <Td> 14.558 </Td> <Td> 15.541 </Td> <Td> 16.524 </Td> <Td> 17.508 </Td> </Tr> <Tr> <Td> 2s </Td> <Td> 6.571 </Td> <Td> 7.392 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 8.214 </Td> <Td> 9.020 </Td> <Td> 9.825 </Td> <Td> 10.629 </Td> <Td> 11.430 </Td> <Td> 12.230 </Td> </Tr> <Tr> <Td> 2p </Td> <Td> 6.802 </Td> <Td> 7.826 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 8.963 </Td> <Td> 9.945 </Td> <Td> 10.961 </Td> <Td> 11.977 </Td> <Td> 12.993 </Td> <Td> 14.008 </Td> </Tr> <Tr> <Td> 3s </Td> <Td> 2.507 </Td> <Td> 3.308 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 4.117 </Td> <Td> 4.903 </Td> <Td> 5.642 </Td> <Td> 6.367 </Td> <Td> 7.068 </Td> <Td> 7.757 </Td> </Tr> <Tr> <Td> 3p </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> 4.066 </Td> <Td> 4.285 </Td> <Td> 4.886 </Td> <Td> 5.482 </Td> <Td> 6.116 </Td> <Td> 6.764 </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Ca </Td> <Td> Sc </Td> <Td> Ti </Td> <Td> V </Td> <Td> Cr </Td> <Td> Mn </Td> <Td> Fe </Td> <Td> Co </Td> <Td> Ni </Td> <Td> Cu </Td> <Td> Zn </Td> <Td> Ga </Td> <Td> Ge </Td> <Td> As </Td> <Td> Se </Td> <Td> Br </Td> <Td> Kr </Td> </Tr> <Tr> <Td> Z </Td> <Td> 19 </Td> <Td> 20 </Td> <Td> 21 </Td> <Td> 22 </Td> <Td> 23 </Td> <Td> 24 </Td> <Td> 25 </Td> <Td> 26 </Td> <Td> 27 </Td> <Td> 28 </Td> <Td> 29 </Td> <Td> 30 </Td> <Td> 31 </Td> <Td> 32 </Td> <Td> 33 </Td> <Td> 34 </Td> <Td> 35 </Td> <Td> 36 </Td> </Tr> <Tr> <Td> 1s </Td> <Td> 18.490 </Td> <Td> 19.473 </Td> <Td> 20.457 </Td> <Td> 21.441 </Td> <Td> 22.426 </Td> <Td> 23.414 </Td> <Td> 24.396 </Td> <Td> 25.381 </Td> <Td> 26.367 </Td> <Td> 27.353 </Td> <Td> 28.339 </Td> <Td> 29.325 </Td> <Td> 30.309 </Td> <Td> 31.294 </Td> <Td> 32.278 </Td> <Td> 33.262 </Td> <Td> 34.247 </Td> <Td> 35.232 </Td> </Tr> <Tr> <Td> 2s </Td> <Td> 13.006 </Td> <Td> 13.776 </Td> <Td> 14.574 </Td> <Td> 15.377 </Td> <Td> 16.181 </Td> <Td> 16.984 </Td> <Td> 17.794 </Td> <Td> 18.599 </Td> <Td> 19.405 </Td> <Td> 20.213 </Td> <Td> 21.020 </Td> <Td> 21.828 </Td> <Td> 22.599 </Td> <Td> 23.365 </Td> <Td> 24.127 </Td> <Td> 24.888 </Td> <Td> 25.643 </Td> <Td> 26.398 </Td> </Tr> <Tr> <Td> 2p </Td> <Td> 15.027 </Td> <Td> 16.041 </Td> <Td> 17.055 </Td> <Td> 18.065 </Td> <Td> 19.073 </Td> <Td> 20.075 </Td> <Td> 21.084 </Td> <Td> 22.089 </Td> <Td> 23.092 </Td> <Td> 24.095 </Td> <Td> 25.097 </Td> <Td> 26.098 </Td> <Td> 27.091 </Td> <Td> 28.082 </Td> <Td> 29.074 </Td> <Td> 30.065 </Td> <Td> 31.056 </Td> <Td> 26.047 </Td> </Tr> <Tr> <Td> 3s </Td> <Td> 8.680 </Td> <Td> 9.602 </Td> <Td> 10.340 </Td> <Td> 11.033 </Td> <Td> 11.709 </Td> <Td> 12.368 </Td> <Td> 13.018 </Td> <Td> 13.676 </Td> <Td> 14.322 </Td> <Td> 14.961 </Td> <Td> 15.594 </Td> <Td> 16.219 </Td> <Td> 16.996 </Td> <Td> 17.790 </Td> <Td> 18.596 </Td> <Td> 19.403 </Td> <Td> 20.219 </Td> <Td> 21.033 </Td> </Tr> <Tr> <Td> 3p </Td> <Td> 7.726 </Td> <Td> 8.658 </Td> <Td> 9.406 </Td> <Td> 10.104 </Td> <Td> 10.785 </Td> <Td> 11.466 </Td> <Td> 12.109 </Td> <Td> 12.778 </Td> <Td> 13.435 </Td> <Td> 14.085 </Td> <Td> 14.731 </Td> <Td> 15.369 </Td> <Td> 16.204 </Td> <Td> 17.014 </Td> <Td> 17.850 </Td> <Td> 18.705 </Td> <Td> 19.571 </Td> <Td> 20.434 </Td> </Tr> <Tr> <Td> 4s </Td> <Td> 3.495 </Td> <Td> 4.398 </Td> <Td> 4.632 </Td> <Td> 4.817 </Td> <Td> 4.981 </Td> <Td> 5.133 </Td> <Td> 5.283 </Td> <Td> 5.434 </Td> <Td> 5.576 </Td> <Td> 5.711 </Td> <Td> 5.842 </Td> <Td> 5.965 </Td> <Td> 7.067 </Td> <Td> 8.044 </Td> <Td> 8.944 </Td> <Td> 9.758 </Td> <Td> 10.553 </Td> <Td> 11.316 </Td> </Tr> <Tr> <Td> 3d </Td> <Td> </Td> <Td> </Td> <Td> 7.120 </Td> <Td> 8.141 </Td> <Td> 8.983 </Td> <Td> 9.757 </Td> <Td> 10.528 </Td> <Td> 11.180 </Td> <Td> 11.855 </Td> <Td> 12.530 </Td> <Td> 13.201 </Td> <Td> 13.878 </Td> <Td> 15.093 </Td> <Td> 16.251 </Td> <Td> 17.378 </Td> <Td> 18.477 </Td> <Td> 19.559 </Td> <Td> 20.626 </Td> </Tr> <Tr> <Td> 4p </Td> <Td_colspan="12"> </Td> <Td> 6.222 </Td> <Td> 6.780 </Td> <Td> 7.449 </Td> <Td> 8.287 </Td> <Td> 9.028 </Td> <Td> 9.338 </Td> </Tr> <Tr> <Td> </Td> <Td> Rb </Td> <Td> Sr </Td> <Td> Y </Td> <Td> Zr </Td> <Td> Nb </Td> <Td> Mo </Td> <Td> Tc </Td> <Td> Ru </Td> <Td> Rh </Td> <Td> Pd </Td> <Td> Ag </Td> <Td> Cd </Td> <Td> In </Td> <Td> Sn </Td> <Td> Sb </Td> <Td> Te </Td> <Td> </Td> <Td> Xe </Td> </Tr> <Tr> <Td> Z </Td> <Td> 37 </Td> <Td> 38 </Td> <Td> 39 </Td> <Td> 40 </Td> <Td> 41 </Td> <Td> 42 </Td> <Td> 43 </Td> <Td> 44 </Td> <Td> 45 </Td> <Td> 46 </Td> <Td> 47 </Td> <Td> 48 </Td> <Td> 49 </Td> <Td> 50 </Td> <Td> 51 </Td> <Td> 52 </Td> <Td> 53 </Td> <Td> 54 </Td> </Tr> <Tr> <Td> 1s </Td> <Td> 36.208 </Td> <Td> 37.191 </Td> <Td> 38.176 </Td> <Td> 39.159 </Td> <Td> 40.142 </Td> <Td> 41.126 </Td> <Td> 42.109 </Td> <Td> 43.092 </Td> <Td> 44.076 </Td> <Td> 45.059 </Td> <Td> 46.042 </Td> <Td> 47.026 </Td> <Td> 48.010 </Td> <Td> 48.992 </Td> <Td> 49.974 </Td> <Td> 50.957 </Td> <Td> 51.939 </Td> <Td> 52.922 </Td> </Tr> <Tr> <Td> 2s </Td> <Td> 27.157 </Td> <Td> 27.902 </Td> <Td> 28.622 </Td> <Td> 29.374 </Td> <Td> 30.125 </Td> <Td> 30.877 </Td> <Td> 31.628 </Td> <Td> 32.380 </Td> <Td> 33.155 </Td> <Td> 33.883 </Td> <Td> 34.634 </Td> <Td> 35.386 </Td> <Td> 36.124 </Td> <Td> 36.859 </Td> <Td> 37.595 </Td> <Td> 38.331 </Td> <Td> 39.067 </Td> <Td> 39.803 </Td> </Tr> <Tr> <Td> 2p </Td> <Td> 33.039 </Td> <Td> 34.030 </Td> <Td> 35.003 </Td> <Td> 35.993 </Td> <Td> 36.982 </Td> <Td> 37.972 </Td> <Td> 38.941 </Td> <Td> 39.951 </Td> <Td> 40.940 </Td> <Td> 41.930 </Td> <Td> 42.919 </Td> <Td> 43.909 </Td> <Td> 44.898 </Td> <Td> 45.885 </Td> <Td> 46.873 </Td> <Td> 47.860 </Td> <Td> 48.847 </Td> <Td> 49.835 </Td> </Tr> <Tr> <Td> 3s </Td> <Td> 21.843 </Td> <Td> 22.664 </Td> <Td> 23.552 </Td> <Td> 24.362 </Td> <Td> 25.172 </Td> <Td> 25.982 </Td> <Td> 26.792 </Td> <Td> 27.601 </Td> <Td> 28.439 </Td> <Td> 29.221 </Td> <Td> 30.031 </Td> <Td> 30.841 </Td> <Td> 31.631 </Td> <Td> 32.420 </Td> <Td> 33.209 </Td> <Td> 33.998 </Td> <Td> 34.787 </Td> <Td> 35.576 </Td> </Tr> <Tr> <Td> 3p </Td> <Td> 21.303 </Td> <Td> 22.168 </Td> <Td> 23.093 </Td> <Td> 23.846 </Td> <Td> 24.616 </Td> <Td> 25.474 </Td> <Td> 26.384 </Td> <Td> 27.221 </Td> <Td> 28.154 </Td> <Td> 29.020 </Td> <Td> 29.809 </Td> <Td> 30.692 </Td> <Td> 31.521 </Td> <Td> 32.353 </Td> <Td> 33.184 </Td> <Td> 34.009 </Td> <Td> 34.841 </Td> <Td> 35.668 </Td> </Tr> <Tr> <Td> 4s </Td> <Td> 12.388 </Td> <Td> 13.444 </Td> <Td> 14.264 </Td> <Td> 14.902 </Td> <Td> 15.283 </Td> <Td> 16.096 </Td> <Td> 17.198 </Td> <Td> 17.656 </Td> <Td> 18.582 </Td> <Td> 18.986 </Td> <Td> 19.865 </Td> <Td> 20.869 </Td> <Td> 21.761 </Td> <Td> 22.658 </Td> <Td> 23.544 </Td> <Td> 24.408 </Td> <Td> 25.297 </Td> <Td> 26.173 </Td> </Tr> <Tr> <Td> 3d </Td> <Td> 21.679 </Td> <Td> 22.726 </Td> <Td> 25.397 </Td> <Td> 25.567 </Td> <Td> 26.247 </Td> <Td> 27.228 </Td> <Td> 28.353 </Td> <Td> 29.359 </Td> <Td> 30.405 </Td> <Td> 31.451 </Td> <Td> 32.540 </Td> <Td> 33.607 </Td> <Td> 34.678 </Td> <Td> 35.742 </Td> <Td> 36.800 </Td> <Td> 37.839 </Td> <Td> 38.901 </Td> <Td> 39.947 </Td> </Tr> <Tr> <Td> 4p </Td> <Td> 10.881 </Td> <Td> 11.932 </Td> <Td> 12.746 </Td> <Td> 13.460 </Td> <Td> 14.084 </Td> <Td> 14.977 </Td> <Td> 15.811 </Td> <Td> 16.435 </Td> <Td> 17.140 </Td> <Td> 17.723 </Td> <Td> 18.562 </Td> <Td> 19.411 </Td> <Td> 20.369 </Td> <Td> 21.265 </Td> <Td> 22.181 </Td> <Td> 23.122 </Td> <Td> 24.030 </Td> <Td> 24.957 </Td> </Tr> <Tr> <Td> 5s </Td> <Td> 4.985 </Td> <Td> 6.071 </Td> <Td> 6.256 </Td> <Td> 6.446 </Td> <Td> 5.921 </Td> <Td> 6.106 </Td> <Td> 7.227 </Td> <Td> 6.485 </Td> <Td> 6.640 </Td> <Td> (empty) </Td> <Td> 6.756 </Td> <Td> 8.192 </Td> <Td> 9.512 </Td> <Td> 10.629 </Td> <Td> 11.617 </Td> <Td> 12.538 </Td> <Td> 13.404 </Td> <Td> 14.218 </Td> </Tr> <Tr> <Td> 4d </Td> <Td> </Td> <Td> </Td> <Td> 15.958 </Td> <Td> 13.072 </Td> <Td> 11.238 </Td> <Td> 11.392 </Td> <Td> 12.882 </Td> <Td> 12.813 </Td> <Td> 13.442 </Td> <Td> 13.618 </Td> <Td> 14.763 </Td> <Td> 15.877 </Td> <Td> 16.942 </Td> <Td> 17.970 </Td> <Td> 18.974 </Td> <Td> 19.960 </Td> <Td> 20.934 </Td> <Td> 21.893 </Td> </Tr> <Tr> <Td> 5p </Td> <Td_colspan="12"> </Td> <Td> 8.470 </Td> <Td> 9.102 </Td> <Td> 9.995 </Td> <Td> 10.809 </Td> <Td> 11.612 </Td> <Td> 12.425 </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> </Td> <Td_colspan="16"> </Td> <Td> He </Td> </Tr>

Calculate the effective nuclear charge for a 3d electron of tc