Rank the ions in order of decreasing size.

Sr2+, Ba2+, Cs

Cs>Ba>Sr

What is the difference between atomic radius, and atomic size

To rank ions in order of decreasing size, you need to consider the size of the ions based on their respective atoms. The general trend is that as you move down a group in the periodic table, the size of the ions increases.

Here's how you can use this information to rank the ions you provided:

1. Cs (Cesium): Cesium is located at the bottom of Group 1 in the periodic table. It has the largest size among the given ions because as you move down the group, the size of the ions increases.

2. Ba2+ (Barium): Barium is located in Group 2 of the periodic table. It has a +2 charge, indicating that it has lost two electrons. Compared to Cs, it is smaller but still larger than Sr2+.

3. Sr2+ (Strontium): Strontium is also located in Group 2 of the periodic table. Similar to Ba2+, it also has a +2 charge. However, since it is located above Ba2+, it is smaller than both Cs and Ba2+.

Therefore, the ranking from largest to smallest is: Cs > Ba2+ > Sr2+

Cs>Ba2+>Sr2+ looks good to me.

I think of atomic size as the diameter or spherical size (volume) whereas the radius is 1/2 the diameter. The small periodic chart I have at home lists the volume.