How would you rank the following elements in order of decreasing atomic size: Ba, Mg, Sr. And why would you choose that oder?

Question

Henry Antrim · Accepted Answer

Atomic size decreases in the order: #Ba#; #Sr#; #Mg#.

Atomic size increases down a group but decreases over a period (from left to right). Three alkaline earth metals are present in your sample: third-period magnesium; fifth-period strontium; and sixth-period barium. It is evident that barium is the largest metal and magnesium is the smallest.

Axel Alvarado · Answer

undefined The order of decreasing atomic size for the elements Ba (barium), Mg (magnesium), and Sr (strontium) is:

Ba > Sr > Mg

This order is based on the trends in the periodic table where atomic size increases down a group. Since Ba is below Sr and Mg in the same group (Group 2), it has the largest atomic size. Among Sr and Mg, Sr has a larger atomic size because it is located below Mg in the same group. Therefore, the order is Ba > Sr > Mg.