![Page 1: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/1.jpg)
The Atom
Section 4.1-4.3 Notes
![Page 2: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/2.jpg)
Some videos…
• http://www.youtube.com/watch?v=caYxrueCHiQ
• You might be giants - Elements
![Page 3: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/3.jpg)
History of Atomic Models
• Democritus (~400BC) – atomos = small, solid, indestructible
particles of different shapes & sizes– These were just ideas, not truly
science…
• Dalton’s Atomic Theory– Billiard Ball Model - small solid
sphere– Developed notion of conservation of
mass and that atoms combine in specific ratios
![Page 4: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/4.jpg)
History of Atomic Models
• J.J. Thomson– Plum Pudding Model - positive
and negative particles dispersed throughout the atom
– Used Cathode Ray tubes to discover the electron - first subatomic particle discovered!
http://www.youtube.com/watch?v=XU8nMKkzbT8
![Page 5: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/5.jpg)
Cathode Ray Tube
• A tube that contains a stream of electrons going from a negative disk (cathode) to a positive disk.
• Deflected stream showed that electrons are negative.
![Page 6: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/6.jpg)
Rutherford– Nuclear Model– Discovered dense positively charged
nucleus of the atom while working with alpha particles• Gold Foil Experiment
![Page 7: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/7.jpg)
![Page 8: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/8.jpg)
History of Atomic Models
• Neils Bohr - – Also Solar System Model– Electrons travel in specific, circular orbits
• Schrodinger & Heisenburg -– Quantum Mechanical Model– Dense nucleus w/ protons & neutrons– Electrons exist in ‘clouds’ called orbitals w/
specific energy levels– Mathematical predictions for probability of
finding electrons– Electrons have particle and wave properties
![Page 9: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/9.jpg)
What do you already know about
atoms?• Brainstorm about what you already
know (or are pretty sure of…) about atoms.
• Write it down on your paper, then we’ll discuss.
![Page 10: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/10.jpg)
How big is the nucleus?!?
Go to atoms videoclip
![Page 11: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/11.jpg)
Comparing subatomic particles…
particle symbolrelative mass (amu)
electron e- 1/1840
proton p+ 1
neutron n0 1
![Page 12: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/12.jpg)
sToP & tHinK
1. If an atom has 2 protons and 2 neutrons, what is its atomic mass in atomic mass units (amu)?
2. What is the charge on an atom that has 7 protons and 7 electrons?
![Page 13: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/13.jpg)
Atomic Number
• # of protons• # of electrons in a NEUTRAL atom• Always a whole number
![Page 14: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/14.jpg)
Mass Number• # of protons + neutrons• in atomic mass units (amu)• Isotopes - atoms of the same
element with different masses– differ in number of neutrons– Examples: Carbon-13 & Carbon-14,
Boron-10 & Boron-11• Element-mass#
![Page 15: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/15.jpg)
![Page 16: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/16.jpg)
![Page 17: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/17.jpg)
Calculating # of neutrons
• Subtract atomic # from mass #• Example:
– Aluminum• 13 protons• 27-13 = 14 neutrons
![Page 18: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/18.jpg)
sToP & tHinK
1. What element has the atomic number 8?2. How many protons, neutrons, and
electrons are in a neutral atom of Potassium (K)?
3. How many protons, neutrons, and electrons are in a neutral atom of Boron-11?
![Page 19: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/19.jpg)
Average Atomic Mass & Molar Mass
• Average mass of all the atoms of a sample for an element
• In amu’s for individual atom• In grams for a mole of that
element = molar mass
![Page 20: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/20.jpg)
Relative Abundance• The atomic mass on the PT is the average
of the isotopes for that element.• Example: Lithium has two isotopes, one
has a mass of 6 amu & one has a mass of 7 amu. Lithium-7 occurs 92.5% of the time…– Multiply the mass by the abundance– Add the two together to get the atomic mass
for the element– What is Lithium’s average atomic mass?
![Page 21: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/21.jpg)
sToP & tHinK
• The published average atomic mass of phosphorus is 30.97. If it has two isotopes, phosphorus-30 and phosphorus-31, which one is more abundant. Explain.
![Page 22: The Atom Section 4.1-4.3 Notes. Some videos… ueCHiQ ueCHiQ You might be giants](https://reader034.vdocument.in/reader034/viewer/2022042821/56649d095503460f949db403/html5/thumbnails/22.jpg)
sToP & tHinK
• An element has two isotopes. One has a mass of 24 amu and represents 70% of the atoms of the element, the other has a mass of 25 amu and represents 30% of the atoms of the element.– What is the average atomic mass?