<p>[SparkNotes:</a> SAT Chemistry: Scoring the SAT II Chemistry](<a href=“http://www.sparknotes.com/testprep/books/sat2/chemistry/chapter2section3.rhtml]SparkNotes:”>http://www.sparknotes.com/testprep/books/sat2/chemistry/chapter2section3.rhtml)</p>
<p>roughly.</p>