Can someone help me with this questions. What do these two photos have in common?

Gallium melts near room temperature and has one of the largest  liquid  ranges of any metal, so it has found use in high temperature thermometers.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom