subatomic particles.pptx

8/10/2019 subatomic particles.pptx

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SUMMARY

PARTS OF

THE ATOM

DISCOVERER

/YEAR EXPERIMENT

PROPOSED

ATOMIC MODEL

ELECTRON

NUCLEUS

NEUTRON ---

Joseph JohnThomson

(1897)

Cathode RayTube

Experiment

Plum PuddingModel/

Raisin BreadModel

ErnestRutherford

(1911)

Gold FoilExperiment

Nuclear Model ofthe Atom

(Rutherford Model

of the Atom)

JamesChadwick

(1932)

Bombardmentof thin sheet ofberyllium with

alpha particles


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German physicist who discovered theproton.

Eugen Goldstein


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PARTICLE MASS (g)CHARGE LOCATION

IN ATOMCOULOMBS

UNIT

CHARGE

PROTON 1.673 X 10-24 +1.602 X 10-19

NEUTRON 1.675 X 10-24 0

ELECTRON 9.109 X 10

-28

-1.602 X 10

-19

+1

0

-1

nucleus

nucleus

Outside

thenucleus

properties of the three key subatomic particles


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Atomic number

Mass number

isotopes


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Atomic number

-Atomic number (Z) is the number of protonsin the nucleus of each atom of an element

-In a neutral atom, the number of proton isequal to the number of electrons, so theatomic number also indicates the number of

electrons present in the atom

-The chemical identity of an atom can be

determined solely from its atomic number.


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https://phet.colorado.edu/sims/html/buil

d-an-atom/latest/build-an-atom_en.html


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mass number

- Mass number (A) is the total number ofprotons and neutrons in the nucleus of anatom of an element.

Mass number = number of protons + number of neutrons

Mass number = atomic number + number of neutrons

Number of neutrons

- The number of neutrons is equal to thedifference between the mass number andthe atomic number (AZ)


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Mass number = proton + neutron


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-The mass number of a particular boron atom is 12and the atomic number is 5. What is the number

of neutrons of this atom?

EXAMPLE

Given:

Mass number (A) = 12

Atomic number (Z) = 5

Number of neutrons = AZ

= 125

= 7


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DALTONS ATOMIC THEORY

1. Matter is composed of tiny indivisible spheres

called atoms.

2. Atoms of the same element are identical,

but atoms of one element are different from

those of all other elements.

3. Atoms cannot be created nor destroyed during a

chemical change.

4. Atoms of different elements combine in simple

whole number ratios to form compounds.


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ISOTOPES

-Atoms of a given element do not all have thesame mass. Most elements have two or moreISOTOPES, atoms that have the same atomicnumber but different mass number.

Example:

There are three isotopes of HYDROGEN:

Protium1 proton and no neutronDeuterium1 proton and 1 neutron

Tritium1 proton and 2 neutrons


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The accepted way to denote the atomic

number and mass number of an atom ofan element (X) is as follows:

X

A

Z

Mass number

atomic number


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Thus, for theisotopes ofhydrogen,we write:

XA

Z

Mass number

atomic number


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Example:

The two common isotopes of Uraniumwith mass numbers 235 and 238:

U238

92U235

92

With the exception of hydrogen, which hasdifferent names for each of its isotopes, isotopes

of elements are identified by their mass

numbers.

Name: Uranium-235Pronounced as

uranium two thirty-five

Name: Uranium-238Pronounced as

uranium two thirty-eight


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ISOTOPES OF CARBON:

SYMBOL NAMENUMBER OFPROTONS

NUMBER OFELECTRONS

NUMBER OFNEUTRONS

C11

6

C12

6

C14

6

C13

6

Carbon - 12

Carbon - 11

Carbon - 13

Carbon - 14

6

6

6

6

6

6

6

6

5

6

7

8


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- The chemical properties of an elementare determined primarily by the protonsand electrons in its atoms; neutrons do

not take part in chemical changes undernormal conditions:

- Isotopes of the same elements have

similar chemistries, forming the sametypes of compounds and displayingsimilar reactivities

IMPORTANT CONCEPTS


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Give the number of protons, neutronsand electrons in each of the followingspecies:

a.)

PRACTICE

Na20

11

Recall:

Superscript = mass number (A)Subscript = atomic number (Z)

Protons = 11

Neutrons = 2011 = 9

Electrons = 11


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b.)

PRACTICE

Na22

11

Recall:


Protons = 11

Neutrons = 2211 = 11

Electrons = 11


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c.)

PRACTICE

O17

8

Recall:


Protons = 8

Neutrons = 178 = 9

Electrons = 8


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c.)

PRACTICE

C14

6

Recall:


Protons = 6

Neutrons = 146 = 8

Electrons = 6


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SYMBOL

ATOMIC

NUMBER

(Z)

MASS

NUMBER

(A)

NUMBER

OF

PROTONS

NUMBER

OF

NEUTRONS

NUMBER

OF

ELECTRONS

Br 80

3 4

14 7

10 19 10

35 35 45 35

Li 3 37

7 7 7N

Ne 9 10

COMPLETE THE TABLE:


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SYMBOL

ATOMIC

NUMBER

(Z)

MASS

NUMBER

(A)

NUMBER

OF

PROTONS

NUMBER

OF

NEUTRONS

NUMBER

OF

ELECTRONS

Al 13 14

29 35

127 53

17 35

13 13

Cu 29 2964

53 53 74I

Cl 18 17

COMPLETE THE TABLE:

27

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REFERENCES


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Chang, Raymond. 2010. Chemistry (10thedition).McGraw-Hill Companies, Inc.

Tillery, Bill. 2012. Physical Science (9thedition). McGraw-HillCompanies, Inc.

https://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html

http://atomic-hair.net/atom.gif

http://2.bp.blogspot.com/-Xe08Ij1qo1U/TcnN1KgfSxI/AAAAAAAAAE0/dfG0jn8wRvU/s1600/boron.gif

http://upload.wikimedia.org/wikipedia/commons/6/6c/Protium deuterium tritium jpg

REFERENCES

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