An ideal gas is confined to an airtight piston that allows the gas to expand and contract but prevents gas from entering or exiting the piston. Initially, the temperature of the gas is 300 Kelvin, and the gas occupies a volume of 10 Liters when an external pressure of 1 atmosphere is applied. The gas is then heated to 600 Kelvin, and the pressure is increased to 5 atmospheres. To one significant figure, what is the new volume of the gas in liters?
4 liters