Others have pointed out the problem, but since you are comparing strings, eq is preferable to == (perlop) 
        if ( $chemical eq $periodicTable[$i][1] ) {

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Also, consider using a hash for your table because it facilitates look-up.

UPDATE: CPAN is a handy resource: Chemistry::Elements

In reply to Re: Array problems. by toolic
in thread Array problems. by thearkranger

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