Subatomic Particles, Atomic Number and Atomic Mass

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Subatomic Particles, Atomic Number and Atomic Mass
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Subatomic particles
Actual mass (g)
Relative mass
Name
Symbol
Charge
Electron
e-
-1
1/1840
9.11 x 10-28
Proton
p
1
1
1.67 x 10-24
Neutron
no
0
1
1.67 x 10-24
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Structure of the Atom

• There are two regions
• 1. The Nucleus
• With protons and neutrons
• Positive charge
• Almost all the mass
• 2. Electron cloud
• Most of the volume of an atom
• The region where the electron can be found

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http//www.andrew.cmu.edu/user/jgrao/Manchester20
United/giant20stadium.jpg
If the atom was the size of a stadium, the
nucleus would be the size of
a marble.
http//www.akronmarbles.com/marble-frag-2.jpg
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Symbols
Contain the symbol of the element, the mass
number and the atomic number
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• The mass number p n
• The atomic number p
• In a neutral atom the e p

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http//chemistry.beloit.edu/Stars/EMSpectrum/fluor
ine.gif
Symbols

• Find the
• number of protons
• number of neutrons
• number of electrons
• Atomic number
• Mass number

http//www.unit5.org/christjs/site20map.htm
8
http//chemistry.beloit.edu/Stars/EMSpectrum/fluor
ine.gif
Symbols

• Find the
• number of protons
• number of neutrons
• number of electrons
• Atomic number
• Mass number

9
10
9
9
19
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Symbols

• Find the
• number of protons
• number of neutrons
• number of electrons
• Atomic number
• Mass number

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Symbols

• Find the
• number of protons
• number of neutrons
• number of electrons
• Atomic number
• Mass number

35
45
35
35
80
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Ions

• In an ion a charged particle the charge can be
  either or -. The of protons and neutrons
  remains the same. It is only the electrons that
  are gained or lost to create the charge
• Mass number p n
• For an ion the e ? p
• adding an electron produces a negative ion
• Subtracting an electron produces a ion

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Symbols

• Find the
• number of protons
• number of neutrons
• number of electrons
• Atomic number
• Mass number

Na
23
1


11


Sodium ion
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Symbols

• Find the
• number of protons
• number of neutrons
• number of electrons
• Atomic number
• Mass number

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Na
23
1
12
10
11
11
23
Sodium ion
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http//www.webelements.com/webelements/elements/me
dia/nearingzero/Na.gif
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Symbols

• If a neutral atom of an element has 78 electrons
  and 117 neutrons what is the
• Number of protons
• Atomic number
• Mass number
• Complete symbol

http//www.findajeweler.com/fashion_trends/2004/Ju
ly/images/pt_sample.gif
http//www.radiochemistry.org/periodictable/elemen
ts/images/78.gif
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Symbols

• If a neutral atom of an element has 78 electrons
  and 117 neutrons what is the
• Number of protons 78
• Atomic number 78
• Mass number 78 117 195
• Complete symbol Pt

http//www.findajeweler.com/fashion_trends/2004/Ju
ly/images/pt_sample.gif
http//www.radiochemistry.org/periodictable/elemen
ts/images/78.gif