Activity 1 Electron Arrangement

8/6/2019 Activity 1 Electron Arrangement

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The Atomic StructureA History Of An Atom

Do you know this person?

D_m_cri_us

John Dalton

Small indivisible ballsimilar to a very tiny ball

Imagined the atom as a smallindivisible ball similar to avery tiny ball


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J.J Thomson

Atom is positive charged

sphere/cloud with electronembedded in it.

He discovers the electron.He described the atom as asphere/cloud of positivecharge which contains a fewnegatively-charged particlescalled electrons.


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Video: Rutherford experiment

Ernest Rutherford

Protons are concentratedin the centre of the atomcalled the nucleus, with acloud of electronssurrounding the nucleus.

He discovers the proton.He suggested that protonsare concentrated in thecentre of the atom called thenucleus, with a cloud ofelectrons surrounding the

nucleus.


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The electrons are moved inshells surrounding the

nucleus.

He suggested that theelectrons are moved indefinite orbits surroundingthe nucleus.He proposed that theelectrons in an atom move inshells around the nucleus

Niels Bohr

James Chadwick

Nucleus consists of

protons and neutrons, withthe nucleus surrounded byelectron shells.


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Video: The Earliest Model

James Chadwick

Nucleus consists ofprotons and neutrons, with

the nucleus surrounded byelectron shells.

He discovered theneutron.He suggested that nucleusconsists of protons andneutrons, with the nucleussurrounded by electronshells.


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Name of scientist ContributionJohn Dalton Matter consists of solid particles

called atoms.

J.J Thomson He discovers the electron. Hesuggested that an atom is positivecharged sphere/cloud with electronembedded in it.

Ernest Rutherford He discovers the proton. Hesuggested that protons areconcentrated in the centre of theatom called the nucleus, with acloud ofelectrons surrounding thenucleus.

Niels Bohr He suggested that the electrons are

moved in definite orbitssurrounding the nucleus.

James Chadwick He discovered the neutron. Hesuggested that nucleus consists ofprotons and neutrons, with thenucleus surrounded by electronshells.

Video: Atom song


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The Properties Of The Subatomic Particles:

PROTONS, ELECTRONS AND NEUTRONS

Subatomicparticle

Symbol Relativemass

Charge Location

Proton p 1 +1 In the nucleus

Electron e 1/1840 -1In orbits around the

nucleus

Neutron n 1 0 In the nucleus

Video: Basic Atomic Structures

Proton

number

Element symbol Proton

number

element symbol

1 Hydrogen H 11 Sodium Na2 Helium He 12 Magnesium Mg3 Lithium Li 13 Aluminium Al4 Beryllium Be 14 Silicon Si

5 Boron B 15 Phosphorus P6 Carbon C 16 Sulphur S7 Nitrogen N 17 Chlorine Cl8 Oxygen O 18 Argon Ar 9 Flourine F 19 Potassium K

10 Neon Ne 20 Calcium Ca


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Protons Number and Nucleon Number

1. All elements are made up ofsmall 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 ofan atom.

3. The nucleon number(also known as mass number)of an atom is the sum/total of the number of protonsand neutrons in the atom.

HW: pg. 19 WTO 2.4 no. 1,2pg. 20 QRB no. 1-3

Isotopes and Their Importance

The isotopes of an element are the atoms ofthat element which contain a same number of protons,but a different number of neutrons.

Nucleonnumber A

Symbol of element

Proton number Z

Nucleon number = Number of protons + Number of neutrons

What is isotope?


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Video: IsotopesIsotopes of some element

Element Isotopes

Hydrogen H111 proton0 neutron

H211 proton1 neutron

H311 proton2 neutrons

Carbon C12

6

6 protons6 neutrons

C136

6 protons7 neutrons

C146

6 protons8 neutrons

Oxygen O16

8

8 protons

8 neutrons

O178

8 protons

9 neutrons

O1888 protons10 neutrons

Sulphur S32

16

16 protons16 neutrons

S3416


-

Bromine rB79

35

35 protons44neutrons

rB8135


-

The uses of isotopes in daily life

Field Isotopes applications


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Medical Gamma rays from cobalt- 60 are used to killcancer cell without surgery in patient. Thistreatment is known as radiotherapy.

Medical instrument are sterilized using gamma

rays. Radioactive materials such as iodide-131 are

injected into patients to detect malfunction ofthyroid glands.

Archeology Radioisotope carbon -14 is used to study theage of ancient artifacts.

Agricultural Carbon -14 is used to study the passage ofcarbon in photosynthesis of green plants.

Industrial Isotope sodium-24 is used to detect leakage ofunderground pipes.

HW: pg. 21 WTO 2.5pg. 21 QRC no. 1-4

The Electronic Structure

You must know the electronic structures for the

first 20 elements in The Periodic Table


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Example: Sodium atom

Example: Magnesium atom

First shell: 2 electrons

Second shell: 8 electrons

Third shell: 8 electrons

Nucleus

Na2311

Na

Electron arrangement: 2.8.1

Electronic structure

Number of valence electron : 1

The electrons in the outermostocupied shell are known as valenceelectrons.


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Example: Chlorine atom

The electron arrangement of elements with protonnumber 1 to 20.

Mg24

12



MgNumber of valence electron : 2

Number of proton : 12

Number of electron: 12

Number of neutron: 24-12= 12

Cl35

17



Cl

Number of valence electron : 7

Number of proton : 17

Number of electron: 17

Number of neutron: 35-17= 18


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Element Number of

neutrons

Numberof

protons

Numberof

electrons

Nucleonnumber

Electronarrange-

ment

Numberof

valenceelectrons

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 2Aluminum 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

[Periodic Table: pg. 176 (symbol of element)]


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The electronic structures of elements with protonsnumbers 1 to 20

Hydrogen

EA : 1NVE: 1

Helium

EA: 2

Lithium Beryllium Boron

EA : 2.5NVE: 5

Carbon Nitrogen Oxygen Fluorine Neon

Sodium Magnesium Aluminum Silicon Phosphorus

Sulphur Chlorine Argon Potassium Calcium

EA : Electron arrangement

NVE: Number of valence electron

HW: pg. 22 QRD no. 1 & 2

pg. 25 RQ Obj. 1-6

pg. 26 RQ Sub. no. 1&2


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pg. 26 RQ Ess. no. 2

Kamal Ariffin, SMKDBL 2009

Activity 1 Electron Arrangement

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