The properties of elements repeat periodically when the are arranged by atomic number

(apex) when a cup of water is dropped, as the cup falls, the water in the cup falls out true or false?

How does a noncompetitive inhibitor reduce an enzyme’s activity?

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