Electron valence for junior high school.pptx

Electron valence refers to the number of electrons in the outermost shell (energy level) of an atom. These outer electrons are called valence electrons, and they play a crucial role in how atoms interact and bond with each other to form molecules.

Here's a simple way to understand it for junior high students:

Atoms are made of protons, neutrons, and electrons.
Electrons are arranged in different energy levels or shells around the nucleus of an atom.
The valence electrons are the electrons in the outermost shell.
These valence electrons determine how an atom will bond with other atoms. Atoms with incomplete outer shells often try to gain, lose, or share electrons to become more stable.
For example, the element sodium (Na) has 1 valence electron, while chlorine (Cl) has 7. Sodium will easily give up its 1 valence electron, and chlorine will accept it, forming a bond (this is how table salt, NaCl, is formed).
So, in summary:

Valence electrons are the ones that decide how atoms bond.
Atoms want to have full outer shells, which usually means 8 valence electrons (this is called the octet rule for most elements).

1. Electron valence By Heru Nurgiyanto, M.Pd

2. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s 2 6 10

3. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s H = 1 Orbital notation 1s 2s 2p 1 H 1s 1 2 6 10

4. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s He = 2 Orbital notation 1s 2s 2p 2 He 1s 2 2 6 10

5. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s Li = 3 Orbital notation 1s 2s 2p 3 Li 1s 2 2s 1 2 6 10

6. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s Be = 4 Orbital notation 1s 2s 2p 4 Be 1s 2 2s 2 2 6 10

7. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s B = 5 Orbital notation 1s 2s 2p 5 B 1s 2 2s 2 2p 1 2 6 10

8. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s C = 6 Orbital notation 1s 2s 2p 6 C 1s 2 2s 2 2p 2 2 6 10

9. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s N = 7 Orbital notation 1s 2s 2p 7 N 1s 2 2s 2 2p 3 2 6 10

10. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s O = 8 Orbital notation 1s 2s 2p 8 O 1s 2 2s 2 2p 4 2 6 10

11. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s F = 9 Orbital notation 1s 2s 2p 9 F 1s 2 2s 2 2p 5 2 6 10

12. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s Ne = 10 Orbital notation 1s 2s 2p 10 Ne 1s 2 2s 2 2p 6 2 6 10

13. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s Na = 11 Orbital notation 1s 2s 2p 3s 3p 11 Na 2 6 10 1s 2 2s 2 2p 6 3s 1

14. 8 s 7 s p 6 s p d 5 s p d f 4 s p d f 3 s p d 2 s p 1 s Cl = 17 Orbital notation 1s 2s 2p 3s 3p 17 Cl 2 6 10 1s 2 2s 2 2p 6 3s 2 3p 5