I think D?? I apologize if not-check in other answers to be sure ^^
beryllium, magnesium, strontium,barium<span>, and </span><span>radium. </span>
<span>Scientists ignore the forces of attraction between particles in a gas under ordinary conditions</span><span> because the particles in a gas are apart and moving fast, rather than clustered and moving slow, therefore the forces of attraction are too weak to have a visible effect.</span>