They are arranged in shells
Explanation:
<h2>Radium(Ra)=> </h2>
atomic number=88
<h2>BERYLLIUM (Be)=></h2>
atomic number =4
why is Ra larger than Be
<h3>1. since the atomic number of Ra is greater than Be, the number of electrons is more, which means there are more number of shells present in Ra than Be. </h3><h2>(atomic Radius)</h2>
<h2>2. the more the valence electron (excluding fully filled ones) the less is the nuclear attraction force</h2><h3>since Ra has more valence electron in its outermost shell, the nuclear attraction force is less which means that Ra 's size is greater than Be.</h3>
hope it helps:)
(4) structural formula, isomers are differently structured forms of the same compound.