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ATOMIC THEORY REVIEW. Where did the elements come from?.
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Where did the elements come from? Hydrogen, a little helium and an even smaller amount of lithium were created in the big bang. The universe is about 95% hydrogen. Clouds of hydrogen gas and dust are compressed by gravity into stars. When a star's core runs out of hydrogen, the nuclear reaction pauses, and gravity compresses the star, heating it up enough to fuse helium.
Where did the elements come from? • If the star is big enough it can eventually create all the elements in the periodic table up to iron (through nuclear reactions and gravity). If a giant star explodes (supernova), it will release enough energy to make all the elements heavier than iron. So stars created the first elements!
What is ALL matter made of? ATOMS !!! What are the 3 subatomic particles? Protons Neutrons Electrons
What are the charges of the subatomic particles? protons (+) positive neutrons (0) neutral electrons (-) negative We know that there are the same number of p+ and e- in atoms on the Periodic Table… So What is the overall charge of any atom? The overall charge of any atom is NEUTRAL… the positive charge cancels out the negative charge = 0!!!
What are the masses (amu) of the subatomic particles? p+ = 1amu n = 1amu e- = 0 amu Atomic mass unit (AMU) What is this AMU stuff????? 2.2 lbs= 1 kg 1.66 x 10-27 kg = 1 amu
What are the two areas of an atom? Nucleus Electron Cloud e- P+ & No
Where are the p+, n, and e- located in an atom? p+ in the nucleus no in the nucleus e- in the electron cloud
Where is most of the volume of an atom located? Electron Cloud Nucleus Where is ALL the mass in an atom located?
What does a Bohr model of the atom look like? The nucleus contains the p+ and n… while the electrons “orbit” the nucleus in the energy rings of the e- cloud.
So what are the charges of the different areas? 1. So what is the overall charge of the nucleus? Positive 2. So what is the overall charge of the electron cloud? Negative (opposite charges attract)
QUICK REVIEW- ATOMS protons, neutrons, and electrons Parts of the atom: nucleus and electron cloud Protons + 1 nucleus p+ Neutral (0) neutrons nucleus no 1 Electron cloud _ Electrons e- 0 Sub-atomic particles:.
Energy Levels of the Atom Atoms can have several energy levels. Sometimes they are also called energy rings, shells or orbits. The Nucleus 2e- 8 e- 8 e- 18 e- 18 e- 32e- 32e- P+ N0 1st shell 2nd shell 3rd shell 4th shell 5th shell 6th shell 7th shell
Beginning with Bohr Models • Let’s try a few easy bohr models: Li Be
Bohr Model Practice 6. P 7. F 8. Cl 9. Br 10. Au 1. Ca 2. O 3. Ne 4. K 5.Rb
Ca O Ne K Rb P F Cl Br Au
16. At 17. Ga 18. Rn 19. Ag 20. W More Bohr Model Practice 11. Fr 12. Te 13. Sn 14. Cs 15. Kr
Fr Te Sn Cs Kr At Ga Rn Ag W
Complete the Bohr Models for the following elements. Ne, Ar,Kr and Xe • What 4 patterns or trends did you notice they have in common? • “Predict” what you think Radon’s (Rn) bohr model would look like. • Six rings • Full shell • More massive • All of the rings or shells are full. • They are all in the same group (18) • They gain an energy ring as you go down a period. • They gain more subatomic particles as you go down.
Lets take a look at the Periodic Table! The periods equal the number of energy shells or rings in an atom.
Patterns from the Bohr Models Ne Ar KrXe Radon Bohr Model
26. Tc 27. Ac 28. Zr 29. Po 30. Np Even More Bohr Model Practice! 21. Os 22. Hf 23. Cm 24. Sr 25. Ho (Stop Whining)
Bohr Model H vs. He Draw the bohr models for the following atoms. Explain why we use helium filled balloons instead hydrogen filled balloons at Parties. Energy rings are not filled Energy rings are filled Hydrogen is unstable and flammable and helium is stable!
“Life on the Edge” with Valence Electrons Valence electrons are electrons in the outermost shell of an atom. They determine whether the atom will bond with another atom. How many valence electrons does lithium have here? 1 valence electron Circle the valence electron and label it in your notes
Arrangement of the Periodic Table 1. What atom is this? Oxygen 2. Which subatomic “particle” helped you to determine that this Bohr model was of oxygen? Protons
Arrangement of the Periodic Table 1. The periodic table is arranged according to what? A. Atomic Symbol B. Atomic mass C. Atomic number D. Number of Energy Shells • Do the elements on the periodic table all increase according to their masses? • No!! Can you find where they are not? There are a few of them. Look carefully!
Periodic Table Card Sort Poster Breaking the Code Purpose: This lesson will help you identify many of the patterns that are contained in the periodic table of elements. Use the card sort poster to answer the following questions on your paper.
Do you notice any patterns here as you move down a column on the Periodic Table? Li Na K Rb Gaining more p+, no, and e-. Gaining more mass Gaining more energy rings Can you “predict” how many energy rings a bohr model of Francium (Fr) would have?
Francium (Fr) Bohr Model 1 valence electron Seven energy rings
What Bohr model patterns are you starting to see develop? Periodic Table Patterns The atomic number is the same number as the number of protons and electrons. Atoms get larger as you move down and to the right on the periodic table. As you move from left to right on the periodic table, you gain protons and electrons and neutrons. As you go down from the periodic table, the atom gains another energy shell or orbit.
Metals vs. Non-Metals Stair steps Non-metals • Metals Man made elements and Rare Earth metals
Metalloids on the Periodic Table Periods/ Rows Metalloids FAMILIES/ GROUPS
Properties of Metals • Most elements are metals.88 elements to the left of the stairstep line are metals or metal-like elements. • Tend to have Luster • High density • Ductile • Malleable (shininess) (heavy for their size) (most metals can be made into thin wires) (most metals can be hammered into thin sheets)
Properties of Non-metals • Nonmetals are found to the right of the stair step line. • No luster • Brittle • Not ductile • Not malleable (dull) (breaks easily)
Properties of Metalloids • Metalloidsare elements on both sides of the stair step line. They have properties of both metals and nonmetals. • Solids • Can be shiny or dull • Ductile • Malleable
Iron (Fe)………….……Ferrum Sodium (Na)….. …….Natrium Gold (Au)……………Aurum Silver (Ag)………….Argentum Potassium (K)………… Kalium Copper (Cu) ………….Cuprum Mercury (Hg) ……Hydragyrum Antimony (Sb)………… Stibium Tin(Sn)….………… Stannum Lead(Pb) ……………..Plumbum Tungsten(W)………….Wolfran So where do the names come from? These abbreviations are for the LATIN names of the elements.
Steps for creating a Bohr model 1. Complete the particle inventory for the atom (protons, electrons and neutrons). 2. Draw your nucleus. 3. Put the number of protons and neutrons in the nucleus. 4. Circle how many electrons you need to use in the shells. 5. Know how many electrons and shells you will need. 6. Put 2 electrons in the first shell. If there are more than 2, begin to fill the next shell (maximum of 8). 7. You cannot begin to fill the next shell until the previous shell is filled. 8. Remember` how many electrons each shell can hold a maximum of. (2, 8, 8, 18, 18, 32, 32,)
30 30 35 54 54 131 79 197 79 80 201 80 53 53 30
Yttrium Manganese 18e 2e 8e 8e 3e 7e 2e 8e 8e P39 N50 P25 N30
Germanium Krypton 14e 18e 2e 8e 8e 2e 8e 8e P39 N50 P36 N48