Atoms that contain a full outer shell of 8 electrons, such as helium, sodium, and chlorine, are chemically stable. They attain stability through ionic bonding, where sodium and chlorine transfer electrons to become oppositely charged ions held together by electrostatic attraction, or through covalent bonding, where chlorine atoms share electron pairs to form Cl2. Ionic and covalent bonding allow atoms to attain full outer shells of 8 electrons and thus achieve stability.

2. Normally these elements do not take
part in chemical reactions….
WHY…..?

3. atoms which contain 8 electrons
in their outer most shell can be
considered to be chemically
stable
 The arrangement of 8 electrons
in the outermost shell of atom is
called octet electronic
configuration

4. He atom contains only one shell.
The maximum electron that can
be accommodated in the K shell
is 2. therefore the 2 electron
pattern system of He is stable.

5. HOW THESE ATOMS
ATTAIN STABILITY
Na - 2,8,1
Cl - 2,8,7

6. 2,8,1 2,8,7

7. Na +
Na+ 1e
Cl+1e Cl
-
Na++ Cl
-
NaCl

8. The oppositely charged ions are held
together by electrostatic force of
attraction. Chemical bonding that
involves electrostatic force of
attraction between oppositely charged
ions are called ionic bonding

9. Cl2
…….?
2,8,7 2,8,7

10. Cl2
Formation

11. A covalent bonding is a
chemical bonding that
involves sharing of electron
pairs between atoms
COVALENT BONDING

12. NAJIYA