Both are ions and we should consider the ionic radius, not the atomic radius.
Rubidium ion (Rb+) will have a larger IONIC radius than strontium ion (Sr2+).
Both ions have the same electronic configuration. But strontium ion has more number of protons in the nucleus. Hence it will have greater force of attraction between the nucleus and the valence electrons, resulting in smaller size.
Barium.
calcium
These metals are beryllium, magnesium, calcium, strontium, and barium.
Magnesium is present in group 2 of periodic table which also contains Beryllium, Calcium, Strontium, Barium and Radiium.
Group 2 (alkaline earth metals): beryllium, calcium, magnesium, strontium, barium, radium.
Barium.
calcium
Six elements are there. And they are: beryllium, magnesium, calcium, strontium, barium, radium
Group 2 elements or alkaline earth metals are beryllium, magnesium, calcium, strontium, barium and radium
Magnesium with two electronic shells.
The electronegativity decreases going down Group 2 beryllium:1.5; magnesium:1.2; calcium: 1.0; strontium:1.0; barium:0.9
Beryllium, Magnesium, Calcium, Strontium, Barium and Radium.
Beryllium, Magnesium, Calcium, Strontium, Barium and Radium.
beryllium magnesium calcium strontium barium radium
These metals are beryllium, magnesium, calcium, strontium, and barium.
Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium all have an oxidation state of plus 2.
magnesium, calcium, barium, strontium