well. Mercury is liquid at room temperature – it’s the grey stuff in thermometers. it expands when heated in a controlled way so you can use this property to measure temperature.
Mercury is toxic – it can cause you to have mental health issues… so we have restricted access to it in the lab. but not too long ago science students used to play with it rolling it up and down the bench in the lab… worrying
There are 2 metals that are liquids at room temperature. These include mercury (which melts at the lowest) and bromine. A few others melt when the temperature goes just a litttttle bit above room temperature: francium, cesium, gallium, and rubidium.
mercury is very cool. We used to be able to play with in in our hands in chemistry class when i was a student, but now people are too worried as it can be mildly toxic.. boo! its not that bad unless you handle it regularly or do something silly like swallow it.