As a group, all of the f-block elements (those that use their remaining electrons to fill an f sublevel orbital) are known as the . a.
actinide series
c.
lanthanide series
b.
inner transition metals
d.
transition metals

Which of the following has expanded our knowledge of the universe beyond our solar system the most? a. manned space travel b. the hubble space telescope c. the pioneer and voyager missions d. the international space station