Elements and Atoms.ppt
- 2. Created by G.Baker www.thesciencequeen.net 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.
- 3. Created by G.Baker www.thesciencequeen.net 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 atom, a place called the nucleus. • The electrons orbit the nucleus. Picture from http://education.jlab.org/qa/atom_model_03.gif
- 4. Created by G.Baker www.thesciencequeen.net 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
- 5. Created by G.Baker www.thesciencequeen.net Graphic from http://education.jlab.org/atomtour/fact2.html
- 6. Created by G.Baker www.thesciencequeen.net 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…
- 7. Created by G.Baker www.thesciencequeen.net Periodic Table 8 O Oxygen 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.
- 8. Created by G.Baker www.thesciencequeen.net Atom Models • There are two models of the atoms we will be using in class. • Bohr Model • Lewis Dot Structure
- 9. Created by G.Baker www.thesciencequeen.net 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. + + - -
- 10. Created by G.Baker www.thesciencequeen.net 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.
- 11. Created by G.Baker www.thesciencequeen.net Nucleus 1st shell 2nd shell 3rd shell Adapted from http://www.sciencespot.net/Media/atomsfam.pdf
- 12. Created by G.Baker www.thesciencequeen.net 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.
- 13. Created by G.Baker www.thesciencequeen.net 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
- 14. Created by G.Baker www.thesciencequeen.net So let’s try it…. 3 Li Lithium 7 + + + Protons = 3 Neutrons = 4 (7-3=4) - - - Electrons = 3 2 in the 1st shell, 1 in the 2nd shell
- 15. Created by G.Baker www.thesciencequeen.net 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 • • • • • • + + + + + + + + - - - - - - - -
- 16. Created by G.Baker www.thesciencequeen.net How to… 1. Write the symbol. 2. Start on the right hand side, working your way clockwise around the symbol. 3. Try Lithium
- 17. Created by G.Baker www.thesciencequeen.net 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.