Electron Bonding

atom.gif (1130 bytes) Electron Bonding

Consider Hydrogen:

hydrogen.gif (1767 bytes) The Hydrogen Nucleus has only ONE electron in the outermost shell. Since the first shell is most stable with TWO electrons, Hydrogen will "react" with other atoms in order to build up its outermost shell to the most stable configuration.

There are two ways atoms can build up their outer shells to a more stable arrangement:
1. Donate, or accept an electron from another atom
or ...
2. Share an electron with another atom.

The first arrangement is called "Electrovalent" bonding. The second is called "Covalent" bonding. Hydrogen usually engages in covalent bonding as outline below ...

covalent.gif (2985 bytes)

The two electrons from the two Hydrogen atoms follow a pathway around BOTH nuclei. The result is the same as if each atom had two electrons in their first shell. This arrangement is more stable than having only one electron. This is why Hydrogen exists as a "di-atomic" (two atom) molecule. The formula for Hydrogen gas is: H 2

Electrovalent bonding occurs when one atom releases an electron and another accepts an electron.

Consider Sodium and Chlorine ...

Notice that Sodium has one electron in its outer shell and Chlorine has 7 electrons in its outer shell. If these two atoms are close to each other (and energy is available, eg heat) the Sodium atom will give up its electron and the Chorine atom will take it into its third shell. Chorine will then have eight electrons in its outer shell and so will Sodium. (Sodium's "outer shell" is now shell number two!)

electrovalent.gif (17283 bytes)

As outlined in a later section, the two atoms are now charged and attract each other very strongly. The resulting combination of one Sodium atom with one Chlorine atom is known as Sodium Chloride, or NaCl, or "table salt".

Electron Bonding - QUIZ

Your Name and School -

Do you Certify the answers below to be all your own work? -

1. What are the two basic ways that atoms can attain a stable electron configuration? -

2. Briefly describe the difference between Electrovalent and Covalent bonding.-

3. How many electrons will Magnesium 'donate' in the electrovalent bonding process? -

4. Name four elements that will accept electrons during an electrovalent bonding process? -

5. From the question above (qn 4), how many electrons will each element accept? -

6. What are the "Inert Gases"? -

7. From the previous question (qn 6) Why do the inert gases behave chemically as they do? -

8. What is the URL of a Web page containing information about Electron Bonding (apart from this one)?

Feedback, comments, questions -

(Make sure your NAME and SCHOOL are included.)

This form will be emailed to a 'marker'. You will receive feedback shortly. Satisfactory performance on this and other Quizzes is required for the granting of a "Completion Certificate" for this Course.