Which of the following are correct for real gases?

Value of 'a' is measure of magnitude of intermolecular attractive forces within the gas and is independent of temperature and pressure.

Repulsive interactions between molecules are short range interadction and are significant when molecules are almost in contact.

Boyle point of a real gas depends upon nature of gas.

Real gases show ideal behavior whn conditions of temperature and pressure are such that the intermolecular forces are practically negligible.