An atom is the basic unit of life, and an element is one type of atom or a group of the same type of atoms. All atoms of the same element have the same number of protons. Atoms of different elements differ in the number of protons.
1. Elements & Atoms Created by G.Baker www.thescience
2. 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. Created by G.Baker www.thescienc equeen.net
3. An atom refresher • An atom has three parts: • Proton = positive • Neutron = no charge • Electron = negative • The proton & neutron are found in the center of the Picture from atom, a place called the http://education.jlab.org/qa/atom_model_03.gif nucleus. • The electrons orbit the nucleus. Created by G.Baker www.thescienc equeen.net
4. 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 Created by G.Baker www.thescienc equeen.net
5. Graphic from http://education.jlab.org/atomtour/fact2.html Created by G.Baker www.thescienc equeen.net
6. 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… Created by G.Baker www.thescienc equeen.net
7. Periodic Table Atomic Number: Number of protons 8 and it is also the O number of Symbol: Element’s electrons in an An atom of anfor abbreviation element. the element. Elements Name Oxygen Atomic Mass/Weight: 16 Number of protons + neutrons. Created by G.Baker www.thescienc equeen.net
8. Atom Models • There are two models of the atoms we will be using in class. • Bohr Model • Lewis Dot Structure Created by G.Baker www.thescienc equeen.net
9. Bohr Model • The Bohr Model shows all of the particles in the - atom. • In the center is circles. + Each circle represents a + single neutron or proton. Protons should have a plus or P written on them. - Neutrons should be blank or have an N. • In a circle around the nucleus are the electrons. Electrons should have a minus sign or an e. Created by G.Baker www.thescienc equeen.net
10. Electrons have special • 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. Created by G.Baker www.thescienc equeen.net
11. Nucleus 1st shell 2nd shell 3rd shell Adapted from http://www.sciencespot.net/Media/atomsfam.pdf Created by G.Baker www.thescienc equeen.net
12. Electrons have special • 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. Created by G.Baker www.thescienc equeen.net
13. 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 Li Lithium 7 Created by G.Baker www.thescienc equeen.net
14. So let’s try it…. Protons = 3 - 3 + + Li + - Lithium - 7 Electrons = 3 Neutrons = 4 2 in the 1 shell, 1 in the 2 shell st nd (7-3=4) Created by G.Baker www.thescienc equeen.net
15. 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 •• •• Created by G.Baker www.thescienc equeen.net
16. How to… 1. Write the symbol. 2. Start on the right hand side, working your way clockwise around the symbol. 3. Try Lithium Created by G.Baker www.thescienc equeen.net
17. Your activity… • Using the beans (Lentils are electrons, Lima Beans are protons, and kidney beans are neutrons), create a Bohr model , and then a Lewis dot structure model of each of the first 20 elements. After you have created each model, draw each model on your chart. • Hint to make a chart, use a burrito fold, then fold the top down by 1 ½ inches. Unfold, you now have 3 columns. Label the columns: element, Bohr model, Lewis Dot. Created by G.Baker www.thescienc equeen.net
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