In group 5A there are 5 electrons in the highest occupied energy level of each element.
Work Step by Step
The thing to remember about a main-group element is that the group number tells you the number of valence electrons said element has or number of electrons on occupied energy level as stated in the question. Group 5A has 5 valence electrons, 4A has 4 valence electrons, and 3A has 3 valence electrons. Another way to remember is that 5A is also group 15 and you can think of it as 1(5). Group 4A is group 1(4) and group 3A is group 1(3).