Answer:
Yes, you can determine which one.
Step-by-step explanation:
Hi, there are many factors that can be used to compare the atomic radius of to elements but the most important is the amount of electrons each atom has.
The atomic number represents the amount of protons and electrons (if the element isn't ionized) that the atom has.
The more electrons the atom has, the more energy levels it completes. And each of this levels has a longer radius than the one before it.
So, higher levels completed represent longer atomic radius.
In conclusion, a element with an atomic number 20 greater than the other has 20 more electrons, completed more energy levels and its radius will be longer