chemistry chapter 2 form 4

7/29/2019 chemistry chapter 2 form 4

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CHAPTER 2


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2.1 MATTER

Most of the things thatwe could see in this world

are MATTER


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What is matter?

Matter means:- anything that occupies space &

has mass- made up of tiny & discrete

particles- Exist as element@compound

Next


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A pure substance whichcannot be broken down into

simpler substance physically& chemically

Matter


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Usually made up of

two or more elements

which are chemically

bonded together

Matter


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1. Matter are made up of tiny &discrete particles

2. Size of particles are veryminute ~~ 1x 10-7cm

3. Consist of atoms, moleculesions

Next


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Lets see the particles inbromine liquid

Particle theory


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The smallest particle of an elementand not breakable anymore.

Examples:Atom of hydrogen

atom of magnesium

atom of oxygen

atom of chlorine

H

Mg

Cl

O

Particle theory


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A group of two @ more atoms,which might consist of:

one type of element (Element)

@ different types of element(Compound)


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Examples of element molecules:

Molecule of hydrogen gas

Molecule of oxygen gas

Molecule of chlorine gas


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Examples of compound molecules:

Molecule of water, H2O

Molecule of ammonia, NH3

Molecule of ethanol, C2H5OH

N

C C

Particle theory


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Ions are atoms which havecharge

Positively-charged ion /cation(loss e-)

Negatively charged ion / anion (gain e-)

+

-


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Hydrogen atom Hydrogen ion

Magnesium atom Magnesium ion

Oxygen atom Oxide ion

Chlorine atom Chlorine ion

Particle theory

H+H Lose electron

Mg2+Lose electronMg

O2

-

Gain electronO

Cl-

Gain electronCl

Symbol of element

Examples of ions:


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Kinetic means motion (move) Kinetic theory states that:

1. Matter consist of particles whichconstantly moving


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2. particles move in random motion ,

collide with each other


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A. substance is cooled,

- particles lose kinetic energy- move slower

B. substance is heated,- particles gain kinetic energy- move faster


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Heat energy makes particlesmove faster!!!
http://localhost/var/www/apps/conversion/tmp/scratch_5/Heating%20cooling.exe


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Experiment which supports

the kinetic theory:

Investigating the diffusion of

particles in asolid, liquid and gas


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What is diffusion ?

How diffusion supports the

kinetic theory ?


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Diffusion happens anyway thatdifferent concentration

of particles
http://localhost/var/www/apps/conversion/tmp/scratch_5/diffusion.swf


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Is the rate of diffusion

different in solid, liquid,and gas state?

Lets get an experimentto check it out!!!


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Diffusion in Solid (membrane)
http://localhost/var/www/apps/conversion/tmp/scratch_5/Diffussion%20thru%20membrane.swf


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Diffusion in Liquid ( )


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Diffusion in Gas (air)
http://localhost/var/www/apps/conversion/tmp/scratch_5/diffusion%20in%20air.exe


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Diffusion affected by Density


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The conclusion is.

Diffusion happens in solid, liquid,and gas states

Diffusion occurs slowest in solid,faster in liquid and fastest in gas

Diffusion occurs faster in subtance

with lower density Diffusion supports kinetic energy


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The Physical States of Matter

Solid

Liquid

Gas


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The Arrangement of Particles


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The Shape & Volume of Particles

Th M & E C f


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The Movement & Energy Content of

Particles

Th A F


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The Attraction Force

between Particles


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The Physical Changes of Matter

Freezing

GasLiquid

Solid

MeltingSublimation

Boiling

Condensation

Sublimation

D t i th


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Determine theMelting Point of Naphthalene

Melting point

the temperaturewhich a solid

becomes liquid


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Diagram of heating naphthalene

Q1-Q4 Q5-Q7

Solid naphthalene

Water


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Heating curve of naphthalene

A

CB

D

Temperature / C

Time / minute

79C

Q1-Q4 Q5-Q7


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What is the Melting point?A: 79C

What is the physical state at B-C?A: solid and liquid

Where is point that Melting process started?

A: B

Where is point that Melting process ended?A: C

graph apparatus


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Why the curve of heating has no change at B-C?A: because the heat energy absorbed by

naphthalene molecules to overcome the forces ofattraction to becomes liquid

Why solid naphthalene heated in water ?

A: to ensure a uniform heating

If the melting point of Substance X is 123C, canwe still use water as medium? Why?

A: No. Because its melting point is higher thanthe boiling point of water. We can use oil bath toreplace water. graph apparatusPhysical changes

D t i th


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Determine theFreezing Point of Naphthalene

Freezing point the

temperature which a solutionbecomes solid


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Cooling curve of naphthalene

Q1-Q4 Q5-Q7

79C

E

Temperature / C

G

H

Time / minute

F


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Is the freezing point same with the Melting point?A: Yes, both are 79C

What is the physical state change in thisexperiment?A: Liquid naphthalene changes to solid

Where is the point thatfreezing process started?A: F

Where is the point thatfreezing process ended?A: G


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Why the curve of heating has no change at F-G?

A: because the heat energy released during

formation of bonds is equal to the heat released tosurroundings

Why liquid naphthalene in the boiling tube is cooled

inside a conical flask?

A: to ensure a uniform cooling


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Different solution has differentboiling point & freezing point


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Diagram of cooling naphthalene

Q1-Q4 Q5-Q7

Liquid naphthalene

Empty conical flask


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2.2 ATOMIC STRUCTURE

Th Hi t i l D l t Of


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The Historical Development OfAtomic Models

John Dalton

imagine atom as aindivisible tiny ball

J.J. Thomsondiscovered electrons

Ernest Rutherford

discovered proton,mass of atom concentrated in nucleus

Neils Bohrproposed the electrons

move in shells around the nucleus James Chadwick proved the existence

of neutrons

S b i P i l I A A


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Subatomic Particle In An Atom

S b i P i l I A A


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Proton

Neutron

Electron

S b t i P ti l I A At


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Proton Electron

Neutron

Nucleus

of atom Electron

shells


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PROPERTIES PROTON NEUTRON ELECTRON

Symbol

Electric Charge

Relative MassLocation



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Symbol p

Electric Charge




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Symbol p n

Electric Charge




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Symbol p n e-

Electric Charge




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Symbol p n e-

Electric Charge +1




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Symbol p n e-

Electric Charge +1 0




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Symbol p n e-

Electric Charge +1 0 -1




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Symbol p n e-


Relative Mass 1Location



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Symbol p n e-


Relative Mass 1 1Location



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Symbol p n e-


Relative Mass 1 1 1/1240 0Location



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Symbol p n e-


Relative Mass 1 1 1/1240 0Location in the

nucleusatom



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Symbol p n e-



nucleusatom

in thenucleusatom



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Symbol p n e-



nucleusatom

in thenucleusatom

Electronshells whicharound the

nucleus atom


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Symbol of Element


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40

20CaNucleon number

Proton number

Symbol of Element

-When an atom is neutral ,(1.refer ions)

its number of proton = e-

- number of protons = 20

so number of elecrons = 20- 2.electron configuration = 2.8.8.2

valence electron = 2

Symbol of element

3.Next


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Electron Configuration

Also known as electron arrangement

How electrons fill into the shells?


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Helium He

Proton number 2

2

Hydrogen H

Proton number 1

1

Lithium Li

Proton number 3

2 . 1

Beryllium Be

Proton number 4

2 . 2


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Boron B

proton number 5

2 . 3

Carbon C

Proton number 6

2 . 4

Nitrogen N

Proton number 7

2 . 5

Oxygen O

Proton number 8

2 . 6

Fluorine F Neon Ne


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Proton number 9

2 . 7

Proton number 10

2 . 8

Sodium Na

Proton number 11

2 . 8 . 1

Magnesium Mg

Proton number 12

2 . 8 . 2

Aluminium Al

P t b 13Silicon Si


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Proton number 13

2 . 8 . 3

Proton number 14

2 . 8 . 4

Phosphorus P

Proton number 15

2 . 8 . 5

Sulphur S

Proton number 16

2 . 8 . 6

Chlorine Cl Argon Ar


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Chlorine Cl

Proton number 17

2 . 8 . 7

Argon Ar

Proton number 18

2 . 8 . 8

Potassium K

Proton number 19

2 . 8 . 8 . 1

Calcium Ca

Proton number 20

2 . 8 . 8 . 2

C l i


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Conclusion:

1st Shell: max 2 e-2nd Shell: max 8 e-

3rd Shell: max 8 e-

1) Because they have the same


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) ynumber of orbits, they have 2

orbits / electron shells2) Group 1 is alkaline metals,

hydrogen is a type of gas /hydrogen is not alkaline metal3) They have stable// electron

arrangement (Helium, pn=2

duplet, Argon, 2.8.8 octet)


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4) Li, Be, B, C, N,O,Br, Ne

5) i) K, Ca, Mgii) C, S, Cl

ARRANGEMENT OF SHELLS IN AN ATOM


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NUCLEUS

2 ELECTRONS

8 ELECTRONS

8ELECTRONS

18 ELECTRONS

1

23

4

Electron arrangement in the


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Electron arrangement in the

carbon atom

C12

6

proton number = 6

number of protons = 6

number of electrons = 6

2 . 4

= electron

nucleus

Number of valence

electrons = 4


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23

11 Na

2 . 8 . 1

number of protons = 11

proton number = 11

number of electrons = 11

= electron

Nucleus

Number of valence

electrons = 1 Symbol of element


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Draw & state the electron arrangement of

the elements below

X

15

7 Y

24

12 Z

39

19


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Let us learn somechemical words !!

P t b ( )


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Proton number (p) number of protons in the nucleus of atom

Nucleon number (p+n)total number of protons and neutrons inthe nucleus of atom

3. Valence electron the electrons in the outermost shell

4. Electron configuration arrangement of electron

Repeat them !!


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epeat t e !!Proton number

number of protons in the nucleus of atomNucleon number

total number of protons and nucleons

in the nucleus of atomValence electron

the electrons in the outermost shell

Electron configuration arrangement of electron

T h !!!


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Try this out!!!

Q1 Fill in the blanks


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Elements Proton

Number

Nucleon

Number

Number

ofNeutrons

A 3 7

B 6 12

C 19 10

D 16 16

E 17 18

F 40 20


Q1 Answers


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Elements Proton

Number

Nucleon

Number

Number

ofNeutrons

A 3 7 4

B 6 12 6

C 9 19 10

D 16 32 16

E 17 35 18

F 20 40 20

Q1 Answers



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Elements NumberofNeutron

NucleonNumber Numberofelectrons

ElectronConfiguration

A 5 9

B 8 2.6C 19 2.7

D 14 2.8.3

E 32 16

F 20 40


Q2 Answers


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Elements NumberofNeutron

NucleonNumber Numberofelectrons

ElectronConfiguration

A 5 9 4 2.2

B 8 16 8 2.6C 10 19 9 2.7

D 14 27 13 2.8.3

E 16 32 16 2.8.6

F 20 40 20 2.8.8.2

Q2 Answers

2 3 ISOTOPES


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2.3 ISOTOPES

What is isotopes?


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Isotopes is just like twins,

same genetic but different of DNA

atoms of the same element withsame number of protons butdifferent number of neutrons

What is isotopes?


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Examples of Isotopes Take a look at Wikipedia isotopes table

Hydrogen :

Graphite :

Oxygen :

1

1

H3

1

H2

1

H

12

6C

14

6C

13

6C

16

8O18

8O17

8O

Isotopes of Hydrogen
http://localhost/var/www/apps/conversion/tmp/scratch_5/Isotope%20table%20(complete)%20-%20Wikipedia,%20the%20free%20encyclopedia.htmhttp://localhost/var/www/apps/conversion/tmp/scratch_5/Isotope%20table%20(complete)%20-%20Wikipedia,%20the%20free%20encyclopedia.htm


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Isotopes of Hydrogen

Hydrogen :

1

1

H

2

1

H

3

1

H


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Properties of isotopesOxygenIsotopes

No of proton

No of neutron

No of e-

e- configuration

Valence e-

16

8O

18

8O17

8O


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No of proton 8

No of neutron

No of e-

e

-

configurationValence e-

16

8O

18

8O17

8O


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No of proton 8 8

No of neutron

No of e-

e

-


16

8O

18

8O17

8O


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No of proton 8 8 8

No of neutron

No of e-

e

-


16

8O

18

8O17

8O


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No of proton 16 16 16

No of neutron 16

No of e-

e

-


16

8O

18

8O17

8O


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No of neutron 16 17

No of e-

e

-


16

8O

18

8O17

8O


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No of neutron 16 17 18

No of e-

e

-


16

8O

18

8O17

8O


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No of e- 16

e- configuration

Valence e-

16

8O

18

8O17

8O


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No of e- 16 16

e- configuration

Valence e-

16

8O

18

8O17

8O


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No of e- 16 16 16

e- configuration

Valence e-

16

8O

18

8O17

8O


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No of e- 16 16 16

e- configuration 2.8.6

Valence e-

16

8O

18

8O17

8O


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No of e- 16 16 16

e- configuration 2.8.6 2.8.6

Valence e-

16

8O

18

8O17

8O


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No of e- 16 16 16

e- configuration 2.8.6 2.8.6 2.8.6

Valence e-

16

8O

18

8O17

8O


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No of e- 16 16 16


Valence e- 6

16

8O

18

8O17

8O


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No of e- 16 16 16


Valence e- 6 6

16

8O

18

8O17

8O


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No of e- 16 16 16


Valence e- 6 6 6

16

8O

18

8O17

8O

Conclusion:


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Conclusion:

Number of valence electron are same

The chemical properties also same

The physical properties might besame, might be different

Try this out!!!


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Try this out!!!

Q3. Answer the structure questions


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Elements Proton Number Nucleon Number

P 3 7

Q 9 19

R 16 32

S 15 31T 16 33

U 18 40

a ) What means proton number?


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A: The numbers of proton in the nucleus of an atom

b) What means nucleon number?A: The numbers of proton & neutron in the nucleus

of an atom

c) Write the electron arrangement for element Q.

A: 2.7

d) How many valence electrons that element Q has?

A: 7

e) How many electron shells that element Q has?

A: two

f) Which pair of elements are isotopes? Explain.

A R & T


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4018

U

A: R & T.

Because they have same proton number but

different nucleon number

g) Is R&T have same chemical properties? Why?

A: Yes. Because they have same valence electron

h) How many protons, neutrons, and electrons are

there in atom S?

A: 15 protons, 16 neutrons and 15 electrons

i) Write the symbol to represent atom U.A: 40

18U


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chemistry chapter 2 form 4

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