It depends on what group or family the element is in. For example, Potassium is in the first group of family so it only has 1 valence electron. However, since nitrogen is in the 15 group of family, it does not have 15 valence electrons. For double digit families, you just take the second digit, and that is the number of valence electrons. Therefore, Nitrogen would have 5 valence electrons.
Valency
You can determine how many valence electrons an atom has by what family the element of the atom is in. For instance, if the element is in family 8A, the number of valence electrons will be 8. Or, if the element is in family 2A, the number of valence electrons for the atom will be 2. So, whatever number family the atom is in, the number of valence electrons equals that.
Group 1, which are the Alkali Metals.
The group-1 family is alkali metals. It has one valence electron.
Elements in the sodium family (Group 1A or Group 1) have 1 valence electron. This is because they have one electron in their outermost energy level.
One valence electron.
It depends on what group or family the element is in. For example, Potassium is in the first group of family so it only has 1 valence electron. However, since nitrogen is in the 15 group of family, it does not have 15 valence electrons. For double digit families, you just take the second digit, and that is the number of valence electrons. Therefore, Nitrogen would have 5 valence electrons.
Valency
In the periodic table, elements in the same family/group have similar chemical properties because they have the same number of valence electrons, giving them similar reactivity. Elements in the same period/row have the same number of electron shells but different properties due to varying numbers of valence electrons. Transition metals are located in the d-block and have varying oxidation states and reactivity.
You can determine how many valence electrons an atom has by what family the element of the atom is in. For instance, if the element is in family 8A, the number of valence electrons will be 8. Or, if the element is in family 2A, the number of valence electrons for the atom will be 2. So, whatever number family the atom is in, the number of valence electrons equals that.
a single electron in their outer valence shell
Group 1, which are the Alkali Metals.
The group-1 family is alkali metals. It has one valence electron.
Transition metals
No, the lithium family is not a reactive group of mostly nonmetals with 7 valence electrons. The lithium family, also known as the alkali metals group, includes lithium, sodium, potassium, rubidium, cesium, and francium. These elements are metals and have 1 valence electron.
All elements in the group of Nitrogen, such as Phosphorus and Arsenic, have five valence electron when in their natural state (that is, they have not have not gained or lost valence electrons). But as to the element in that group that has valence electrons in the third electron orbital, Phosphorus is the one you are looking for. To figure this out, just look at the Periodic Table of Elements, and you will see that Phosphorus is in the third row. Hope this helps!