Question

use the periodic table to answer the following questions.
what is the predicted order of first ionization energies from highest to lowest for beryllium, calcium, magnesium, and strontium?
$ce{be > ca > mg > sr}$
$ce{be > mg > ca > sr}$
$ce{ca > sr > be > mg}$
$ce{sr > ca > mg > be}$

Explanation:

All elements are in Group 2 of the periodic table. First ionization energy decreases down a group as atomic radius increases, making it easier to remove an outer electron. The order of the elements from top to bottom in Group 2 is Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), so their first ionization energies follow the reverse order from highest to lowest.

Answer:

Be > Mg > Ca > Sr