Which of these statements is true?
a.
some molecules may contain no atoms.
b.
some elements found in nature exist as molecules.
c.
some compounds include only one type of element.
d.
some atoms are made of two or more different elements.

Select the correct answer from each drop-down menu. to make a table of the elements, dmitri mendeleev sorted the elements according to their . he then split the list of elements into several columns so that elements beside each other had similar .