Because attraction of water molecules around an ion depends on. that ion's density of charge, smaller ions (and thus ions of greater ionic. potenti. al) attract more water molecules. The result is the. inverse. relationship. between non-hydrated radius and hydrated radius shown below.
[v. 5] In Hebron he reigned over Judah seven years and six months: and in Jerusalem he reigned thirty and three years over all Israel and Judah.   This would have made David 37 when he became king of all Israel. Do not get confused between 'Judah' and 'Israel': they are not the same.
David's first child by Bathsheba died seven days after birth. One of David's sons, Absalom, killed his half-brother Amnon, after Amnon raped Absalom's sister, Tamar. Later, Absalom revolted against his father David and tried to take over the throne, but was killed by Joab, David's army commander. Another son of David, Adonijah, was killed soon after David died. David was king for about 40 years.