<p><strong>বিশেষ্য:</strong></p><ul><li>একটি দৈর্ঘ্যের একক, <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>1</mn><msup><mn>0</mn><mrow><mo>−</mo><mn>15</mn></mrow></msup></mrow><annotation encoding="application/x-tex">10^{-15}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height: 0.8141em;"></span><span class="mord">1</span><span class="mord"><span class="mord">0</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height: 0.8141em;"><span style="top: -3.063em; margin-right: 0.05em;"><span class="pstrut" style="height: 2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mtight">−</span><span class="mord mtight">15</span></span></span></span></span></span></span></span></span></span></span></span> মি, যা পারমাণবিক দূরত্ব মাপতে ব্যবহৃত হয়।</li></ul>