With the temperature held constant at 300 K, use the Select mass slider to place weights on the lid. Record the pressure and volume of the gas for each added mass. Added mass on the lid Total mass Pressure Volume
(Lid + added mass)
0 kg 10 kg
10 kg 20 kg
20 kg 30 kg
30 kg 40 kg

Solution :

When the temperature is held constant at 300 K, we can use the Select mass slider in order to place the weights on the lid. And we record the pressure and also the volume of the gas for each of the added mass.

Added mass  on the lid       Total mass               Pressure             Volume

          0 kg                                10 kg                    98.1        

          10 kg                               20 kg                            

          20 kg                              30 kg                            

          30 kg                               40 kg                            

As the pressure increases at a constant temperature, the volume of the gas decreases.

Thus we can see that the pressure is inversely proportional to the volume.          

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

the answer is b & c i believe : )