"st">'A'</span>])</span>
<span id="cb6-6"><a href="#cb6-6" aria-hidden="true" tabindex="-1"></a><span class="bu">print</span>(mass_dict[<span class="st">'K'</span>])</span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
<div class="cell-output cell-output-stdout">
<pre><code>71.0371138
128.094963</code></pre>
</div>
</div>
</section>
</section>
<section id="isotopes" class="level2">
<h2 class="anchored" data-anchor-id="isotopes">Isotopes</h2>
<p>We d