system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What causes mercury to be so toxic while gallium is safe and shares simular properties?
gpt
Gallium is not safe nor is it similar to mercury except that both are liquid at relatively low temperatures. Gallium is in group 13 and is similar to aluminum and indium.

Mercury can also be easily absorbed and gallium is very difficult to absorb.