A major difference between the two rows of inner transition elements is that the lanthanides _____.

a.are radioactive and the actinides are not
b.occur in nature while most of the actinides are synthetic
c.are gases at room temperature and the actinides are solids
d.have no uses while the actinides have many

Question

A major difference between the two rows of inner transition elements is that the lanthanides _____. 
    

   a.are radioactive and the actinides are not
   b.occur in nature while most of the actinides are synthetic
   c.are gases at room temperature and the actinides are solids
    d.have no uses while the actinides have many

anonymous · Answer

well I know that Actinides are radioactive.  So that at least helps narrow down the options.  "All actinides are radioactive and release energy upon radioactive decay"-Wikipedia

chmvijay · Answer

it s b) most of lanthanides occur in nature where as mos of actinides are synthetic , which are formed in nuclear reaction.