Earth has an iron-nickel core which gives us a magnetosphere. **Based on [this question][2] that replaces our iron core with a mercury core, would we be likely get a magnetosphere?**

Mercury is highly conductive and forms mercury(Hg ii) crystals at high pressures. At low temperatures and high pressures it becomes superconductive. Given the conductivity, mercury *might* form a magnetosphere but I'm just not sure. 

What happens to the crust or how life might form on such a planet is outside the question scope but if you'd like to speculate on these topics or on how the planet was formed, you are welcome to do so. 

[2]:http://worldbuilding.stackexchange.com/q/27277/10364