3x-12=0

what is the value of x​

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

Which is true of a liquid? it has a definite volume but not a definite mass.it has a definite mass but not a definite volume.it has a definite volume but not a definite shape.it has a definite shape but not a definite volume.

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j