The existence of this metal, which already becomes liquid at 29 degrees, was predicted by Mendeleev in his theory of the periodic table. Its potential remained undiscovered for a long time, but today gallium is an important component of semiconductor materials due to its special properties.

To the article about gallium on the website Fascination Chemistry

Because of its low melting point, gallium can be melted by hand. But you shouldn't necessarily do that. There are enough people who have already done that and have put videos on the Internet, for example this video. The effect can also be seen in the Gallium video from the Periodic Videos series.