Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because...
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Transcript of Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because...
![Page 1: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/1.jpg)
Elements & Atoms
![Page 2: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/2.jpg)
Models of the Atom
![Page 3: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/3.jpg)
Why do scientists used models?
• Scientists make models because reality is complex. It is useful to use a model because it helps us understand what cannot be seen with our own eyes. Models are necessary in science. However you must remember that a model is only a representation of the real thing.
• Allow scientists to study objects that are impossible to study. Models help scientists analyze and make predictions.
![Page 4: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/4.jpg)
Limitations Models have
• A model deals only with a portion of a system
• It may not predict the behavior of the real system accurately
• Ex. Models of the atom cannot accurately represent the distance between the particles or the motion of the electrons
![Page 5: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/5.jpg)
An atom refresher
• Matter is anything that takes up space and has mass.
• All matter is made of atoms
• Atoms are the building blocks of matter, sort of how bricks are the building blocks of houses.
• An atom is the smallest whole particle of matter.
• Sub-Atomic particles are smaller than atoms and are the tiny particles that an atom is made of.
![Page 6: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/6.jpg)
An atom • An atom has three parts:
• Proton = positive (Much larger and heavier than electrons)
• Neutron = no charge (Large and heavy like protons)
• Electron = negative (tiny and very light)
• The proton & neutron are found in the center of the atom, a place called the nucleus.
• The electrons orbit the nucleus.
Picture from http://education.jlab.org/qa/atom_model_03.gif
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Atomic Structure
![Page 8: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/8.jpg)
What are elements?
• Elements are the alphabet to the language of molecules.
• To make molecules, you must have elements.
• Elements are made of atoms. While the atoms may have different weights and organization, they are all built in the same way.
Information & picture from Chem4kids at http://www.chem4kids.com/files/atom_structure.html
![Page 9: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/9.jpg)
Graphic from http://education.jlab.org/atomtour/fact2.html
![Page 10: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/10.jpg)
More about Elements..
• Elements are the building blocks of all matter.
• The periodic table is a list of all of the elements that can build matter. It’s a little like the alphabet of chemistry.
• The periodic table tells us several things…
![Page 11: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/11.jpg)
Periodic Table
8
OOxygen
16
Atomic Number:
Number of protons and it is also the number of electrons in an atom of an element.
Element’s Symbol:An abbreviation for the element.
Elements Name
Atomic Mass/Weight:
Number of protons + neutrons.
![Page 12: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/12.jpg)
Electrons have special rules….
• You can’t just shove all of the electrons into the first orbit of an electron.
• Electrons live in something called shells or energy levels.
• Only so many can be in any certain shell.
• The electrons in the outer most shell of any element are called valance electrons.
![Page 13: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/13.jpg)
Created by G.Baker Created by G.Baker www.thesciencequeen.netwww.thesciencequeen.net
NucleusNucleus
11stst shell shell
22ndnd shell shell
33rdrd shell shell
Adapted from http://www.sciencespot.net/Media/atomsfam.pdf
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So let’s try it….• How to draw a Lithium atom
• First, look at the Periodic Table
• Second, determine the number of protons (Look @ the atomic number)
• Then determine the number of neutrons (Atomic mass – atomic number)
• Then determine the number of electrons (Look @ the atomic number)
3
LiLithium
7
![Page 15: Elements & Atoms. Models of the Atom Why do scientists used models? Scientists make models because reality is complex. It is useful to use a model because.](https://reader036.fdocuments.net/reader036/viewer/2022062515/56649f445503460f94c6566c/html5/thumbnails/15.jpg)
So let’s try it….
3
LiLithium
7
++
++++
Protons = 3
Neutrons = 4
(7-3=4)
--
--
--
Electrons = 3 Electrons = 3
2 in the 12 in the 1stst shell, 1 in the 2 shell, 1 in the 2ndnd shell shell
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Lewis Dot Structure
• The Lewis Dot Structure is a bit different from the Bohr model.
• It only shows the element symbol and it’s outer most electron shell.
O• ••• •
•
++ ++
++ ++
++
++++
++
--
--
-- --
----
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