They are typically the electrons which are involved in forming bonds to other atoms (as opposed to the other so-called "core" electrons which do not interact much with other atoms or molecules. (This is for WHAT they are not what they DO) (stupid answer by the way man)
A fluorine atom has seven valence electrons, as do all halogens.
A nitrogen atom has 5 valence elctrons. To figure that out you have to count across the row that atom is in and stop at it and the number you counted up to is the number of valence electrons. So... 1st Lithium 2nd is Beryllium 3d is Boron then Carbon then 5th is Nitrogen. Your Welcome)
The number of protons and electrons in an atom determine its chemical properties. Specifically, the number of electrons in the outermost energy level (valence electrons) dictates how likely the atom is to react with other atoms to achieve a stable electron configuration.
An atom will be least likely to form chemical bonds when its valence electron shell is full. This typically occurs when the atom is a noble gas with a stable configuration, such as helium, neon, or argon. Atoms in this state are already stable and do not need to gain, lose, or share electrons to achieve a full valence shell.
Elements that have one valence electron tend to be highly reactive and readily form positive ions by losing that electron to achieve a stable electron configuration. These elements include alkali metals like lithium, sodium, and potassium.
8
7.
Valence elctrons are involved in chemical reactions.
Copper has 4
The 2 electrons from 3s orbital.
For group 12 to 17 you have to subtract 10 to get the valence elctrons.
A fluorine atom has seven valence electrons, as do all halogens.
They are either shared (covalent bond) or one donates and the other takes the elctrons (ionic bond).
16 elctrons
3
This is a chemical element. You can find the how many electron in a single atom by using a Periodic Table.
A nitrogen atom has 5 valence elctrons. To figure that out you have to count across the row that atom is in and stop at it and the number you counted up to is the number of valence electrons. So... 1st Lithium 2nd is Beryllium 3d is Boron then Carbon then 5th is Nitrogen. Your Welcome)