Detailed calculations show that the value of Zeff for the outermost electrons in Na and K atoms is 2.51+ and 3.49+, respectively. (e) Predict Zeff for the outermost electrons in the Rb atom based on the calculations for Na and K.

Video transcript

Hi everyone for this problem. It reads the effective nuclear charge of an electron for the outermost electrons and magnesium and calcium atoms derived from a set of quantum mechanical calculations are positive 3. and 4.40 respectively. Based on the trend for the values calculated for magnesium and calcium, estimate the effective nuclear charge value of for the strontium atom. Okay, so we want to calculate the effective nuclear charge of the strontium atom. And magnesium and calcium are on the same column in the periodic table. Alright, so looking at that right below calcium is strontium And we can approximate that the change in effective nuclear charge from magnesium to calcium will be the same as from calcium to strontium. Alright, so we're going to go ahead and take the difference between the quantum mechanical calculations so we have 4. -3.31 is equal to 1.09. So from 4.40, we're going to add the expected change. So 1.09 is our expected change and we're going to add 1. To 4.40. Okay, So we get 4 5.49. We can estimate this or Approximated to 5.50. And this is going to be our answer. Alright, this is going to be the estimated effective nuclear charge value for the strontium atom. That's it for this problem. I hope this was helpful