500 mL of He at 98 kPa expands to 750 mL. Find P2.

0.65atm or 65.3kPa

Explanation:

Given parameters:

Initial volume of He  = 500mL

Initial pressure  = 98kPa, this gives 0.967atm

Final volume  = 750mL

Unknown:

Final pressure  = ?

Solution:

A good grasp of Boyle's law should suffice here. The law states that:

 "the volume of a fixed mass of gas varies inversely as the pressure changes if the temperature is constant".

            Mathematically;

                P₁ V₁  = P₂ V₂

where P and V are pressure and volume

           1 and 2 are the initial and final states;

  Now, solve for the unknown P₂;

             0.967 x 500  = P₂ x 750

                   P₂  = 0.65atm or 65.3kPa

that's what i got you can count the number of atoms

a electronegativity decreases beacuse the size of nucleus is bigger.