Learning Objectives

The number of electrons in an electrically-neutral atom is the same as the number of protons in the nucleus. Therefore, the number of electrons in neutral atom of Boron is 5. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z – 1) negative electrons in the atom. Explanation: Boron, B, is located in period 2, group 13 of the periodic table, and has an atomic number equal to 5. This means that a neutral boron atom will have a total of 5 electrons surrounding its nucleus. Now, your tool of choice here will be boron's electron configuration, which looks like this. Boron has 3 valence protons to satisfy and thus needs 3 valence electrons. The problem is that this is either 3 lone electrons on boron, 3 bonds to boron, or some combination of bonds/electrons. With this, the largest number of electrons you can get on a neutrally charged boron is 6 (when boron has 3 bonds). If boron gains an additional bond, it will get 8 electrons and satisfy its octet, but. Boron Number of Valence Electrons. Leave a Comment Cancel reply. Name Email Website. Save my name, email, and website in this browser for the next time I.

• Define valence electron.
• Be able to indicate valence electrons when given the electron configuration for an atom.

What makes a particular element very reactive and another element non-reactive?

A chemical reaction involves either electron removal, electron addition, or electron sharing. The path a specific element will take depends on where the electrons are in the atom and how many there are.

In the study of chemical reactivity, we will find that the electrons in the outermost principal energy level are very important and so they are given a special name. Valence electrons are the electrons in the highest occupied principal energy level of an atom. In the second period elements listed above, the two electrons in the 1 s sublevel are called inner-shell electrons and are not involved directly in the element’s reactivity or in the formation of compounds. Lithium has a single electron in the second principal energy level and so we say that lithium has one valence electron. Beryllium has two valence electrons. How many valence electrons does boron have? You must recognize that the second principal energy level consists of both the 2 s and the 2 p Inprocomm driver download. sublevels and so the answer is three. In fact, the number of valence electrons goes up by one for each step across a period until the last element is reached. Neon, with its configuration ending in s²p⁶, has eight valence electrons.

Summary

• Valence electrons are the outer-shell electrons of an atom.
• Valence electrons determine the reactivity of an atom.

Practice

What Is The Valence Of Boron

Use the link below to answer questions about valence electrons:

Review

1. Define valence electron.
2. Define inner shell electron.
3. How many valence electrons are there in fluorine?
4. What are the 2s electrons in nitrogen?
5. How many inner shell electrons are there in beryllium?

Glossary

• inner-shell electrons: Those electrons that are not in the outer shell and are not involved in the reactivity of the element.
• valence electrons: The electrons in the highest occupied principal energy level of an atom.

List Of Valence Electrons For Each Element

References

How Many Valence Electrons In Boron

Boron Valence Electron Count

1. User:Chemicalinterest/Wikipedia. http://commons.wikimedia.org/wiki/File:Cobalt_carbonate.JPG.