The pressure p, of a gas varies inversely with its volume, v. pressure is measured in units of pa. suppose that a particular amount of a gas is initially at a pressure of 84 pa at a volume of 36 l. if the volume is expanded to 216 l, what will the new pressure be?

Y = k/x is the INVERSE function equation, where k is the constant of variation.
Using Pressure and Volume: P = k/V
The first step is to find k, the constant of variation. This number will not change in the equation for finding volume or pressure.
Using the given data:
 84 = k/36
multiply both sides by 36.
3024 = k so the equation is P = 3024/V
P = 3024 / 216
P = 14

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table