Question

helium, co2,o2, arrange then in solubility order in water at 298k and 1atm​

Answer 1

He<CO2<O2

hope it helps you friend!

Answer 2

helium, co2,o2,  solubility order in water at 298k and 1atm​:

order: $He > CO_{2} > O_{2}$

Carbon dioxide is more soluble in water as compared to oxygen gas. Some fraction of carbon dissolved forms carbonic acid with water and it is readily dissolvable because of formation of strong hydrogen bonds. Oxygen in dissolved form is necessary for survival of aquatic life and it forms weak vander waal bonds.