How is mercury's crust and why is like tht?

Question

pllzzz be very clear n specifict

Answer 1

Not sure what you mean by "how is Mercury's crust".   Usually "how is" is a question about state or condition (like asking "how is Mary feeling").  

Maybe you mean "how was Mercury's crust formed", or "what is Mercury's crust made of".

Mercury's surface is very similar in appearance to that of the Moon, showing extensive mare-like plains and heavy cratering, indicating that it has been geologically inactive for billions of years.

Mercury was heavily bombarded by comets and asteroids during and after its formation 4.6 billion years ago, as well as during the "late heavy bombardment" period that ended about 3.8 billion years ago.  During this time, Mercury received impacts over its entire surface - since it had no atmosphere, there was nothing to slow the meteors and nothing to erode the craters.

So far only about 55% of the surface has been mapped in sufficient detail to say much about its geology (this was done by Mariner 10 in 1974-5 and will be continued by Messenger).  Mercury's interior contains a large metal core (likely nickel/iron) that accounts for about 42% of its volume.  Part of this core may still be liquid resulting in the weak global magnetosphere.

Answer 2

It is because of surface tension.