<span>Groups are vertical, numbered 1 through 18, and have similar properties, so answer D. Most of the properties of groups are defined by the outermost electron in the shells of the elements. Horizontal delineations in the Periodic Table are known as periods.</span>
A solution may exist in any phase so your answer is D. any of the above
hope this helps :)
<span><span>4.2×1022</span>NA</span><span> N_{A} is the avagadro number</span>
