00:01
Hello, so let's write down some of our given information.
00:03
We have our screening constant, which is negative 2 point, let me actually write that on the left here, negative 2 .90 au for the 1s, 2s configuration.
00:16
And then we can now calculate the effective nuclear charge for each configuration.
00:21
And we're going to use that with this equation e is equal to negative z squared over n squared and so we can now account for both electrons for each configuration.
00:39
We sum the energies of both electrons adjusting for electron -electron interactions as necessary based on the configuration.
00:45
So now to calculate the screening constant given the binding energy of negative 2 .9 for a 1s2 or 1s2, whether it's s or p configuration, we can infer the screening constant used to calculate this energy.
00:59
Normally for helium and hydrogen, like 1s2s or p configuration without screening, the total binding energy ignoring electron -electron repulsion would be 2 times negative z squared over 1, which technically 1 squared, but because 1 squared is 1, we'll just leave it at 1.
01:20
Au with z equals 2 for helium.
01:27
However, the actual binding energy is lower due to electron electron repulsion, which is accounted for by the screening constant...