the atomic nucleus
DESCRIPTION
The Atomic Nucleus. Review…the nucleus. The nucleus is composed of particles called nucleons..__ & __ Neutrons and protons have the same mass, with ___ being slightly greater. Neutrons have nearly 2000 times the mass of _____. protons and neutrons neutrons electrons. Review…the atom. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/1.jpg)
The Atomic Nucleus
![Page 2: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/2.jpg)
Review…the nucleus
The nucleus is composed of particles called nucleons..__ & __
Neutrons and protons have the same mass, with ___ being slightly greater.
Neutrons have nearly 2000 times the mass of
_____.
protons and neutrons
neutrons
electrons
![Page 3: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/3.jpg)
Review…the atomThe mass of an atom is
almost equal to the mass of the _____ alone
Nucleons are bound together by an attractive nuclear force called the ____ force
The positively charged protons in the nucleus hold the negatively charged electrons in their ____
nucleus
strong
orbits
![Page 4: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/4.jpg)
Review…the atom
The number of ___ in the nucleus determines the chemical properties of the atom
The # of protons determines the # of ____ that orbit the atom
The # of ___ has no direct effect on the # of electrons
protons
![Page 5: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/5.jpg)
Review…the atomThe principal role of the
neutrons in the nucleus is to act as a sort of ____ to hold the nucleus together
The electrical force acts as a ____ force between protons
The atom needs a certain balance of neutrons and protons for ___
cement
repulsive
stability
![Page 6: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/6.jpg)
The symbol was created in 1946 UC- Berkeley to represent “activity
coming out of a atom”
![Page 7: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/7.jpg)
What is Radioactivity?
Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves.
There are numerous types of radioactive decay. The general idea:
An unstable nucleus releases energy to become more stable
![Page 8: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/8.jpg)
Radioactive Decay
![Page 9: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/9.jpg)
Radioactive Decay
A neutron is very unstable. A lone neutron will spontaneously decay into a proton + an electron.
If you have a lot of neutrons, within 11 minutes ½ of them will have decayed
Particles that decay are said to be radioactive
A lone neutron is radioactive
![Page 10: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/10.jpg)
All the elements heavier than Bismuth (At # All the elements heavier than Bismuth (At # 83)83)
![Page 11: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/11.jpg)
Their atoms emit 3 things…alpha, beta Their atoms emit 3 things…alpha, beta particlesparticles and gamma and gamma raysrays
![Page 12: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/12.jpg)
![Page 13: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/13.jpg)
![Page 14: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/14.jpg)
![Page 15: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/15.jpg)
![Page 16: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/16.jpg)
![Page 17: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/17.jpg)
![Page 18: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/18.jpg)
Which is more penetrating?Which is more penetrating?
![Page 19: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/19.jpg)
Radioactive Isotope
Iodine-131, a beta emitter, is taken as sodium iodide in drinking water. Almost all of it will find its way to the thyroid
![Page 20: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/20.jpg)
IsotopesIsotopes
They are atoms of the same element that have different numbers of neutrons.
![Page 21: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/21.jpg)
![Page 22: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/22.jpg)
![Page 23: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/23.jpg)
![Page 24: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/24.jpg)
![Page 25: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/25.jpg)
![Page 26: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/26.jpg)
![Page 27: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/27.jpg)
![Page 28: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/28.jpg)
Radioactive Half-life
![Page 29: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/29.jpg)
Radioactive Half-Life
The half-life of an element is the time it takes for half of the material you started with to decay Remember, it doesn’t matter how much you start with. After 1 half-life, half of it will have decayed.
Each element decays into a new elementC14 decays into N14 while U238 decays into
Pb206 (lead), etcThe half-life of each element is constant. It’s
like a clock keeping perfect time
![Page 30: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/30.jpg)
Half-life
![Page 31: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/31.jpg)
Half-life
![Page 32: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/32.jpg)
Half-life
![Page 33: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/33.jpg)
Half-lifeHalf-life
![Page 34: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/34.jpg)
“How much of this element remains after 4 half-lives?
Just remember that at the endof one half-life, 50% of theelement will remain. Find 50%on the vertical axis, Follow theblue line over to the red curveand drop straight down to findthe answer:
![Page 35: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/35.jpg)
Carbon DatingCarbon Dating
The radioactivity of once living things decreases at a predictable rate
![Page 36: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/36.jpg)
Uranium DatingUranium Dating
The dating of older, non-living things (like rocks) is accomplished by radioactive minerals, such as Uranium. Uranium decays very slowly.
Rocks on Earth have been dated to 3.7 bil yrs oldRocks on Moon dated to 4.2 bil yrs old
The Earth has been dated to 4.6 bil yrs old
![Page 37: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/37.jpg)
Review…whew!
https://archive.org/details/NASARealWorldMath_WhatIsRadioactiveDecay_HD
http://en.wikipedia.org/wiki/Barium_swallow
![Page 38: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/38.jpg)
Radiation Penetrating PowerRadiation Penetrating Power
![Page 39: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/39.jpg)
Three Common Types of Radioactive Emissions - Penetrability
Alpha particles may be completely stopped by a sheet of paper, beta particles by aluminum shielding. Gamma rays, however, can only be reduced by much more substantial obstacles, such as a very thick piece of lead.
![Page 40: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/40.jpg)
Radiation Penetrating PowerRadiation Penetrating Power
http://www.passmyexams.co.uk/GCSE/physics/penetrating-properties-of-radiation.html
![Page 41: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/41.jpg)
Radiation and You (and me)!
http://people.chem.duke.edu/~jds/cruise_chem/nuclear/exposure.html
![Page 42: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/42.jpg)
Is there radon in your home?
![Page 43: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/43.jpg)
Sources of Radioactivity
Primordial - from before the creation of the Earth
Cosmogenic - formed as a result of cosmic ray interactions
Human produced - enhanced or formed due to human actions (minor amounts compared to natural)
![Page 44: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/44.jpg)
Radiation Exposure to Americans
![Page 45: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/45.jpg)
Review
Name three of the science pioneers in the study of Radioactivity.?
Why does a nucleus decay?Order these emissions from least to greatest
penetrability: Gamma, Alpha, Beta.What is the greatest source of exposure to
radioactivity in our everyday lives?
![Page 46: The Atomic Nucleus](https://reader030.vdocument.in/reader030/viewer/2022032805/56813191550346895d9803d9/html5/thumbnails/46.jpg)
Nuclear Fusion - Energy released when two light nuclei combine or fuse
•However, a large amount of energy is required to start a fusion reaction:
o Need this energy to overcome ________ forces of protons.o Extremely high temperatures can provide start-up energy.
repulsion
More energy in fusing hydrogen that fission of uranium