Chapter 7.4, Problem 1CP

Arrange the elements $\text{Ca, Sr, and Ba}$ in order of increasing $I{E}_1$.

$\begin{array}{l}\text{a)}\hfill \\ \text{Ca < Sr < Ba}\hfill \\ \text{b)}\hfill \\ \text{Ba < Sr < Ca}\hfill \\ \text{c)}\hfill \\ \text{Ba < Ca < Sr}\hfill \\ \text{d)}\hfill \\ \text{Sr < Ba < Ca}\hfill \\ \text{e)}\hfill \\ \text{Sr < Ca < Ba}\hfill \end{array}$