If the temperature remains constant and the initial pressure is 101.3 kpa then what is the new pressure reading when the volume is doubled

             The pressure will decrease by half.

Data Given:

                  P₁  =  101.3 kPa  

                  V₁  =  X

                  V₂  =  2X

                   P₂  =  ??

Let us suppose the initial volume is 5 L and the final volume when doubled is 10 L. Then According to Boyle's Law, " The Volume of a given mass of gas at constant temperature is inversely proportional to the applied Pressure". Mathematically the initial and final states of gas are given as,

                                     P₁ V₁  =  P₂ V₂     (1)

Solving equation 1 for P₂,

                                     P₂  =  P₁ V₁ ÷ V₂

Putting values,

                                     P₂  =  (101.3 kPa × 5 L) ÷ 10 L

                                     P₂  =  50.65 kPa

          As the volume is doubled, the pressure is decreased from 101.3 kPa to 50.65 kPa or it has decreased by half.

you need to have a picture of the atom that way we can answer it

it is b that is the answer.