historical atom and atomic structure - mr. sjokvist...structure. • an atom contains protons,...
TRANSCRIPT
![Page 1: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/1.jpg)
1
History and Structure of the AtomFrom Democritus to...
![Page 2: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/2.jpg)
2
History of Atomic Theory
• Democritus (from about 440 BC) • coined the term atom which means uncuttable • He felt that if you kept cutting matter smaller and
smaller eventually you will no longer be able to cut any further.
2
![Page 3: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/3.jpg)
3
John Dalton (1766-1844)3
• Felt that an atom was indivisible • spherical in shape • Model: Sphere • Analogy: Billiard ball
![Page 4: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/4.jpg)
4
JJ Thomson (1856-1940)
• Discovered electrons • Felt that an atom was negatively charged
particles floating in a positive soup • Model: Charges floating around • Analogy: Raisin bun or Plum Pudding
4
![Page 5: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/5.jpg)
The Atom• Thompson proved in 1897 that cathode rays were
particles from inside the “a-tomos” or “un-cuttable” atom
• Nagaoka pictured a planetary model for the atom, with electrons around a central mass
![Page 6: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/6.jpg)
5
Analogy
5
Hantaro Nagaoka (1865-1950)
• Developed the planetary model of atom • Model: Positive sphere with electrons orbiting in a
ring • Analogy: Saturn
![Page 7: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/7.jpg)
66
Ernest Rutherford (1871-1937)
• Discovered the nucleus, the proton and first split an atom
• Model: An atom was a small positively charged nucleus surrounded by electrons orbiting around it.
• Analogy: A beehive
![Page 8: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/8.jpg)
77
Rutherfords Famous Experiment
• Called the Gold Foil Experiment • Alpha particles were fired at thin gold foil • A detector encircled the foil and lit up when hit with
alpha particles. • If the plum pudding model were true it was expected
most particles would go straight through the foil with only slight deflection.
• However, in the experiment, some particles were deflected back at a sharp angle proving the existence of a small, dense, and positively charged nucleus.
![Page 9: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/9.jpg)
8
Text
Plum pudding expected results. Particles all go through.
Actual results. Some are deflected back due to a nucleus
Rutherford's results
![Page 10: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/10.jpg)
Data table for 50 “shots”
# timesStraight Through
Slight Deflection
Bounce Back
IIII II
![Page 11: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/11.jpg)
9
Another view of the experiment9
![Page 12: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/12.jpg)
1010
Niels Bohr
• Worked out details of atomic structure. Notably orbital layers. Solved problems related to Rutherfords model.
• Model: Electrons orbit in rings at different distances from the nucleus.
• Analogy: Planets orbiting the sun
![Page 13: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/13.jpg)
1111
Erwin Schroedinger (1887-1961)
• Major discoveries in quantum mechanics. Nature of electrons in atoms.
• Model: Electrons exist in a probability distribution around the atom. Kind of like a cloud.
• Analogy: A spinning fan blade.
![Page 14: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/14.jpg)
Radioactivity• Marie and Pierre Curie discovered that
some isotopes are unstable: they spontaneously decay and give off radiation
![Page 15: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/15.jpg)
What are the effects of radiation?
![Page 16: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/16.jpg)
Up and Atom!
![Page 17: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/17.jpg)
You wouldn’t like me when I’m angry...
![Page 18: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/18.jpg)
Check your understanding
P. 279 even Steven
![Page 19: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/19.jpg)
![Page 20: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/20.jpg)
12
Quick Quiz: Historical Atom
1. What did Dalton say an atom was like? 2. What did JJ Thomson say an atom was like? 3. What did Rutherford say an atom was like? 4. What are the 3 parts of an atom?
1. A billiard ball, or a pool table ball 2. Raisin bun 3. A beehive 4. Proton, Neutron, Electron
12
![Page 21: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/21.jpg)
13
Parts of the Atom13
The Nucleus
Electrons
![Page 22: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/22.jpg)
14
Parts of the Atom14
The Nucleus
Electrons Mass=0 Charge=-1
Protons Mass=1 Charge=+1
Neutrons Mass=1 Charge=0
![Page 23: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/23.jpg)
1515
Atoms on the Periodic Table
3 Be 7.0
Atomic # = Number of protons
neutrons + protons Atomic mass
![Page 24: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/24.jpg)
16
Try This16
Atomic # Element Symbol Atomic Mass
Be
Na
Fe
I
![Page 25: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/25.jpg)
17
To Determine Other Numbers 17
To find Do this
Proton # same as atomic number
Electron # same as atomic number for neutral atoms
Neutron # =atomic mass-atomic number
Mass =Prot # + Neut#
![Page 26: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/26.jpg)
18
Element Atomic # e- # Mass # Neut #
12
P 15
16 8
18
Fill in the blanks
![Page 27: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/27.jpg)
19
Summary19
• The model of the atom has progressed over time from a simple ball to the mysterious quantum structure.
• An atom contains protons, neutrons and electrons.
• You can calculate the number of each using the atomic number and atomic mass
• Electrons are negative, protons are positive, and neutrons are neutral
![Page 28: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/28.jpg)
Check your understanding
P. 283 Odd Todd
![Page 29: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/29.jpg)
Isotopes• Elements have a characteristic number of
protons, – e.g. Hydrogen always has one proton
• They may have different numbers of neutrons
• Neutrons help to glue together the nucleus of mutually repulsive protons
![Page 30: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/30.jpg)
Radiation
• Radiation from the nucleus comes in three flavors: – α (Alpha): massive, “slow”, low penetration. He2+ – β (Beta): fast, low mass, medium penetration. e- – γ (Gamma): high energy E-M radiation. Gamma ray
photon.
![Page 31: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/31.jpg)
Check your understanding
P. 289 even Stephen
![Page 32: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/32.jpg)
![Page 33: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/33.jpg)
f(x)=100(0.5)^x
-0.5 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
20
40
60
80
100
x
y
% Remaining vs. Half-lives elapsed
![Page 34: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/34.jpg)
• Activity level: • 1 bequerel = Decays per second • Ex: what is the activity level for 12000 decays per
minute?
• 12000decays/60s • =200 Bq
![Page 35: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/35.jpg)
f(x)=100(0.5)^x
-0.5 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
20
40
60
80
100
x
y
% activity vs. Half-lives elapsed
![Page 36: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/36.jpg)
![Page 37: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/37.jpg)
Half Life λ
• When a radioactive isotope decays, the amount remaining can be described by a half life relation:
λt
AA |⎠⎞|⎝
⎛=
2
1
0
• Ex 1: find the amount remaining of 55g of Ne-18 in 26s, if it has a half life of 13 s
![Page 38: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/38.jpg)
λt
AA |⎠⎞|⎝
⎛=
2
1
0
• Ex 1: find the amount remaining of 55g of Ne-18 in 26s, if it has a half life of 13 s
• How many half lives? • 26/13=2
• Amount remaining=55x1/2x1/2=12g
![Page 39: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/39.jpg)
Check your understanding
P. 295 q's 4-9
![Page 40: Historical atom and Atomic Structure - Mr. Sjokvist...structure. • An atom contains protons, neutrons and electrons. • You can calculate the number of each using the atomic number](https://reader034.vdocuments.us/reader034/viewer/2022042622/5fa65f2f8ae8f408f3426ef6/html5/thumbnails/40.jpg)
Chapter Review
P. 295 q's 4-9 Choose 10 vocab p. 302 P. 304 q's 1-10, choose 5 of 11-18