Answer : The correct option is, (3) 750 K and 20 kPa
Explanation :
The conditions for ideal gas are :
Ideal gas are those gas that has no intermolecular attractions.
Ideal gas are those gas that have negligible volume.
The ideal gas equation is,
The conditions for real gas are :
Real gas are those gas that have intermolecular attractions.
Real gas are those gas that have volume.
The real gas equation is,
A real gas behave ideally at high temperature and low pressure condition.
From the given options, option (3) have high temperature and low pressure is the correct option.
Hence, at 750 K and 20 kPa conditions of temperature and pressure does a sample of helium behave most like an ideal gas.