Plastic, or Polystyrene depending on what you prefer, could be a great addition to the game. Plastic will be a great addition since it's a great insulator. 

* Melts at around 300 to 400 degrees celsius and becomes quite brittle at 0 degrees celsius and below. 

* Has about 90 percent light permeability. 

* Not meant to be around high centrifugal forces and is great insulation for electrical currents in wiring. 

* Not suitable for usage below zero. 

* Plastic is resistant to sodium solutions and non-oxidising acids. Fuel, and other substances like it, form cracks in plastic. 

4 digit symbol is PSTC. 

A new gas called Perish. With one like property of Antimatter, Perish destroys particles it touched, but does not stop there. Once one Perish particle touches a particle of anything else, sans diamond or wall or hydrogen, that particle explodes violently. The explosion is similar to that of a 9x9 particle tnt bomb. In essence, 100 particles of Perish connecting with 100 particles of anything else result in the like explosion of a 900x900 tnt bomb. The downside is that Perish can only do this if it's above 1,000 degrees celsius. If not at that temperature or above, Perish will only Disentegrate particles without the resulting explosion. 

If Perish comes in contact with hydrogen, the hydrogen will go through nuclear fusion with Perish and will reverse explode. It implodes and the rsult forms a 10 particle diameter black hole. This ensuing black hole will then have the same properties as a normal black hole. 

Another problem with Perish is that it can't travel through any wall. As it's a gas, it moves erratically, but with a purpose. In a place where the pressure gauge is negative, Perish will travel upwards. In a place where pressure is positive, Perish will travel downward. If the pressure gauge is at 0, or even, the Perish particles will stay right where they are clicked by the mouse. 

the four digit symbol for Perish is PRIH. 

@Solace (View Post)

 Additionally, Perish is colored based on the pressure it's at. At pressure 0, Perish is #281714. At negative pressure, Perish is #272727. At positive pressure, Perish is #270701. When Perish mixes with Hydrogen and goes through nuclear fusion, it becomes this colour #3E3F5D and Expands to twice its original size, IE 100 particles becomes 200 particles, and implodes, forming a 10 by 10, circular black hole with positive pressure of 256. When the Perish infused hydrogen ball implodes, everything in a 100 particles, circular radius, deletes itself. 

Perish can also be created from antimatter with a 9999 tmp and 99 tmp2 value. 

You cannot change it's ctype. It's temperature will never change. The temperature is always to stay 100 celsius. 

@Sandwichlizard (View Post)

 it's 100 degrees when it's alone. By fuzing with hydrogen, it's no longer just perish.