Both ammonia (nh3) and phosphine (ph3) are soluble in water. which is least soluble and why? phosphine because it does not form hydrogen bonds with water molecules phosphine because the p-h bonds are so strong that they cannot break to enable phosphine to hydrogen-bond with water ammonia because the n-h bonds are so strong that they cannot break to enable the ammonia to hydrogen-bond with water ammonia because it does not form hydrogen bonds with water mole

            Phosphine is least soluble because it does not form hydrogen bonds with water molecules.

Explanation:

                   Hydrogen Bonding interactions are created between two molecules having a Hydrogen atom attached to most electronegative atom like Fluorine, Oxygen and Nitrogen on one molecule and the the most electronegative atom of the second molecule.

                    In given case, water contains a most electronegative atom like Oxygen, also it contains hydrogen directly attached to oxygen but in Phosphine (PH₃) there is no most electronegative atom as Phosphorous is less electronegative.

                    Hence, Phosphine fails to develop Hydrogen bonding with water molecules therefore it is less soluble than NH₃.

oh it is true if thats what you are asking

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.