How many elements are there in world

Which sentence best describes the formation of igneous rock? a- lava on the surface dries up and makes arock b_melted rocks cools and forms crystals c_rocks under tremendous heat and pressure d_magma is melted rock underground

If i initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 k, and then i raise the pressure to 14 atm and increase the temperature to 300 k, what is the new volume of the gas?

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?