<p>JHU “applicants are strongly encouraged to submit up to three SAT subject tests.”
Strongly encouraged for top tier schools essentially means do it because of the competition you’ll face. </p>
<p>Source: [Johns</a> Hopkins University Office of Undergraduate Admissions - Apply - Standardized Test Requirements](<a href=“http://apply.jhu.edu/apply/testreqs.html]Johns”>http://apply.jhu.edu/apply/testreqs.html)</p>
<p>So yes you might as well take chemistry to get the 3rd subject test in. Note that subject tests won’t necessarily make up for a B at IVYs. Getting a good score can certainly boost your chances though.</p>