Question

Why nh3 h2o hf are liquids while ph3 h2s hcl are gases?

Answer 1

because the intermolecular force of attraction in PH3, H2S, HCL is very low so the molecules are far away from each other. so these are gases.

while on the other hand , the intermolecular force of attraction in NH3, H2O, HF is high as compared to liquid so the molecules are close to each other and this is why they are liquid