{{infobox element isotopes/isotopes stable | mn=6 | sym=Li | na=7[{{val|0.59%019}}, {{val|0.078}}]<ref name="Atomic Weight of Lithium">{{Cite web|title=Atomic Weight of Lithium|url=https://ciaaw.org/lithium.htm|url-status=live|access-date=6 October 2021|website=CIAAW}}</ref> | n=3 |firstlinks=yes}}
{{infobox element isotopes/isotopes stable | mn=7 | sym=Li | na=92[{{val|0.41%922}}, {{val|0.981}}]<ref name="Atomic Weight of Lithium"/> | n=4 |firstlinks=no}}
|standard atomic weight=[{{val|6.938}}, {{val|6.997}}]<ref name="Atomic Weight of Lithium"/>
|isotopes table footnote=<sup>6</sup>Li content may be as low as 1.9% in<br/>commercial samples. <sup>7</sup>Li would therefore<br/>have a content of up to 98.1%.