✟ 神秘の科学城 ✟: 十一月 2013

✟ 神秘の科学城 ✟: 十一月 2013

SPM Form 4 Chemistry Notes — Chapter 2『2.4』The Electronic Structure of an Atom

2.4 The Electronic Structure of An Atom

Elements

Proton Number

Number of Electron

Number of Electron in shell

Electron Arrangement

Number of Valence Electron

1

2

3

4

Hydrogen

1

1

1

1

1

Helium

2

2

2

2

2

Lithium

3

3

2

1

2.1

1

Beryllium

4

4

2

2

2.2

2

Boron

5

5

2

3

2.3

3

Carbon

6

6

2

4

2.4

4

Nitrogen

7

7

2

5

2.5

5

Oxygen

8

8

2

6

2.6

6

Fluorine

9

9

2

7

2.7

7

Neon

10

10

2

8

2.8

8

Sodium

11

11

2

8

1

2.8.1

1

Magnesium

12

12

2

8

2

2.8.2

2

Aluminium

13

13

2

8

3

2.8.3

3

Silicon

14

14

2

8

4

2.8.4

4

Phosphorus

15

15

2

8

5

2.8.5

5

Sulphur

16

16

2

8

6

2.8.6

6

Chlorine

17

17

2

8

7

2.8.7

7

Argon

18

18

2

8

8

2.8.8

8

Potassium

19

19

2

8

8

1

2.8.8.1

1

Calcium

20

20

2

8

8

2

2.8.8.2

2

Valence Electron

● Valance electrons are electrons in the outermost shell of an atom.

Periodic Table of The Elements

● In Periodic Table，elements are arranged in the increasing order of the proton number.

● All elements in same group（vertical column） have the same number of valence electrons.

● The elements of a period（horizontal rows） have the same number of electron occupied shells.