Cs and Na are solids in room temperature while F and Xe are gases.
The number of electrons in the outermost shell of an atom will determine its reactivity. Out of the gases given Xe and F, F ( the most electronegative element) posses 5 valence shell electrons which makes it highly reactive while Xe which is a noble gas posses 8 valence shell electrons which makes it less reactive compared to many elements.
<span>The answer is: This is a cell (B) with a nucleus (C) containing DNA (A). The DNA is organized into chromosomes (D). A section of the chromosome that codes for a trait is called a gene (E).</span>
