If jupiter doesn’t have any land, its only gas, how does it have a gravitational pull? And how did it get created?

Question: If jupiter doesn't have any land, its only gas, how does it have a gravitational pull? And how did it get created?
- Keywords:
  gas,
  gravity,
  jupiter
Asked by halestone to Asif, Laura, Lena, Sean, Viv on 16 Mar 2012.
- Sean Murphy answered on 16 Mar 2012:
  
  Gravity works on everything that has mass. While Jupiter is made of some solid, liquid and mostly gas, this solid/liquid/gas still has a really really large mass, therefore it also has a large gravitational pull. Jupiter formed the same time as the rest of the solar system did 4.6 billion years ago. A rocky core coalesced and then hydrogen and helium was attracted gravitationally to the core.

Question: If jupiter doesn't have any land, its only gas, how does it have a gravitational pull? And how did it get created?