Saturday, July 14, 2012

Chemistry Form 4 Notes – Chapter 2: Atomic Structure[Atom]

The Atomic Structure
 
A History Of An Atom

John Dalton  info
Imagined the atom as a small indivisible ball similar to a very tiny ball.
 
J.J Thomson info
He discovers the electron.
He described the atom as a sphere/cloud of positive charge which contains a few negatively-charged particles called electrons.


Ernest Rutherford info
He discovers the proton.
He suggested that protons are concentrated in the center of the atom called the nucleus, with a cloud of electrons surrounding the nucleus

 

Niels Bohr   info
He suggested that the electrons are moved in definite orbits surrounding the nucleus.
 


James Chadwick info
He discovered the neutron. He suggested that nucleus consists of protons and neutrons, with the nucleus surrounded by electron shells.

 
 The Atom SONG


The Properties Of The Subatomic Particles:

PROTONS, ELECTRONS AND NEUTRONS
Subatomic particle
Symbol
Relative mass
Charge
Location
Proton
p
1
+1
In the nucleus
Electron
e
1/1840
-1
In orbits around the nucleus
Neutron
n
1
0
In the nucleus

First 20 Element:

Proton number
Element
symbol

Proton number
element
symbol
1
Hydrogen
H

11
Sodium
Na
2
Helium
He

12
Magnesium
Mg
3
Lithium
Li

13
Aluminium
Al
4
Beryllium
Be

14
Silicon
Si
5
Boron
B

15
Phosphorus
P
6
Carbon
C

16
Sulphur
S
7
Nitrogen
N

17
Chlorine
Cl
8
Oxygen
O

18
Argon
Ar
9
Flourine
F

19
Potassium
K
10
Neon
Ne

20
Calcium
Ca


Protons Number and Nucleon Number
  1. All elements are made up of small invisible particles called atoms.
  2. The proton number (also known as the atomic number) of an atom is the number of protons in the nucleus of an atom.
  3. The nucleon number (also known as mass number)    of an atom is the sum/total of the number of protons and neutrons in the atom.
 
 Remember!!!!
Nucleon number =   Number of protons + Number of neutrons

 
Isotopes and Their Importance
The isotopes of an element are the atoms of that element which contain a same number of protons, but a different number of neutrons.

 Example:

 
The uses of isotopes in daily life
 
Field
Isotopes applications
Medical
·      Gamma rays from cobalt- 60 are used to kill cancer cell without surgery in patient. This treatment is known as radiotherapy.
·      Medical instrument are sterilized using gamma rays.
·      Radioactive materials such as iodide-131 are injected into patients to detect malfunction of thyroid glands.
Archeology
·      Radioisotope carbon -14 is used to study the age of ancient artifacts.
Agricultural
·      Carbon -14 is used to study the passage of carbon in photosynthesis of green plants.
Industrial
·      Isotope sodium-24 is used to detect leakage of underground  pipes.

 The ATOMIC Structure
 
You must know the electronic structures for the first 20 elements in The Periodic Table
 
 
The electron arrangement of elements with proton number 1 to 20.
 
Element
Number of neutrons
Number of protons
Number of electrons
Nucleon number
Electron arrange-ment
Number of valence electrons
Hydrogen
0
1
1
1
1
1
Helium
2
2
2
4
2
2
Lithium
4
3
3
7
2.1
1
Beryllium
5
4
4
9
2.2
2
Boron
6
5
5
11
2.3
3
Carbon
6
6
6
12
2.4
4
Nitrogen
7
7
7
14
2.5
5
Oxygen
8
8
8
16
2.6
6
Fluorine
10
9
9
19
2.7
7
Neon
10
10
10
20
2.8
8
Sodium
12
11
11
23
2.8.1
1
Magnesium
12
12
12
24
2.8.2
2
Aluminum
14
13
13
27
2.8.3
3
Silicon
14
14
14
28
2.8.4
4
Phosphorus
16
15
15
31
2.8.5
5
Sulphur
16
16
16
32
2.8.6
6
Chlorine
18
17
17
35
2.8.7
7
Argon
22
18
18
40
2.8.8
8
Potassium
20
19
19
39
2.8.8.1
1
Calcium
20
20
20
40
2.8.8.2
2

 so...Hopefully anda telah faham tentang atom...Pastikan anda mengingat 20 unsur pertama ini. Anda juga perlu mahir dalam melukis struktur atom tersebut.
ok...jom kita rehat jap, dengar lagu 20 unsur pertama:...jumpa anda di BAB 3

2 comments:

  1. I cherish the online journal. Extraordinary post. It is genuine, individuals must figure out how to learn before they can learn. lol i know it sounds entertaining however it genuine. perniagaan internet

    ReplyDelete
  2. macam mana nak tengok full jadual arrangement element tu.sebb nampak separuh jer

    ReplyDelete

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