Liquid helium:
The chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (about 4 K or −452.2 °F). Its boiling point and critical point depend on which isotope of helium is present: the common isotope helium-4 or the rare isotope helium-3.
en.wikipedia.org
液氦:
液氦（Liquid helium）是指在極低溫的攝氏溫標-269 °C（約等於熱力學溫標4 K或者是華氏溫標-452.2 °F）時成為液體的氦，該化學元素的沸點與臨界點取自於氦的同位素：較為常見的氦-4與較為少見的氦-3。
zh.wikipedia.org
This article uses material from the Wikipedia articles %@, which are released under the Creative Commons Attribution-Share-Alike License 3.0.
Liquid helium液氦