Answer:
The atom with one outer most electron is sodium
The atom with two outermost electrons is magnesium
The atom with five outermost electrons is phosphorus
Step-by-step explanation:
A dot structure of an atom shows the number of electrons present on the outermost shell of that atom. In order words, a dot structure shows the valence electrons present on the valence shell of an atom.
Sodium has an atomic number of 11, hence the electrons are arranged in three shells in the following order 2,8,1. This implies that one electron is present on it's outermost shell.
Magnesium has an atomic number of 12. Its electrons are arranged in shells in the order; 2,8,2. Hence, two electrons are present in its outermost shell.
Phosphorus contains 15 electrons(atomic number of 15), these electrons are arranged in shells in the order 2,8,5. Hence there are five outermost electrons present in phosphorus.