The correct answer is Be+
That is because it lost a single electron but still has the same number of protons, and thus the effective charge attracting each electron is greater, which in turn makes the radius even smaller
Rubidium or strontium have larger a larger atomic radius since the further left on the periodic table you go, the larger the sizes of the atoms are. This trend can be explained through effective nuclear charge which explains how the further left and down you go, the less the atoms nucleus is able to pull in the electrons around it.<span />
Answer:
The stable isotopes of carbon are carbon-12 (12C) and carbon-13 (13C).
I hope this helps! :)
