Question

complete the puzzel. word down-name of solid non metal. word accorss-name of the metalloid used in solar cell ending alphabet is n

Answer 1

Solution :-

Word Down -

The name of the solid non-metal is Diamond, which is also the hardest substance on Earth. 

Word Across -

The name of the metalloid used in solar cells is Silicon, which ends with alphabet 'n'.

So, the right answer is -

                          D
                           I
                          A
                          M
                          O
              SILICON
                          D 

Answer 2

Thank you for asking this question.
The solid non metal is carbon and pure form of carbon in nature is "diamond" so diamond is the answer here. And naturally it is also the hardest material found on earth.

Also as regard to metalloid  used in solar cell is "Silicon" also its name end with the word "n". ( from "diamond" word across you can drive silicon word easily) 
Silicon is used as semiconductor in solar cell and helps in capturing of sun light energy.