Presentation on theme: "What subatomic particle is not located in the nucleus?"— Presentation transcript:
1 What subatomic particle is not located in the nucleus? BELL RINGERWhat subatomic particle is not located in the nucleus?
2 Atomic History Research Chapter 3Review Book – Topic 1Chapter 1
3 What are the nucleons (things in the nucleus)? BELL RINGERWhat are the nucleons (things in the nucleus)?
4 Quiz Who did the gold foil experiment? Who first named an atom? According to Bohr, where are electrons located?Draw an atom according to Democritus.Who discovered the electron?
5 History - Greeks Earth, Wind, Water, Fire! A. Ancient Greece (2000+ years ago)Democritus- believed that matter could not be continuously divided- Matter consists of small indivisible particles“Atomos” = Atom indivisible- Aristotle did not agree his teacherParticles are in continuous motionFour elements make up all matter and energyEarth,Wind,Water,Fire!No scientific evidence to show this.
6 History by 1700s (scientific revolution), all chemists agreed: on the existence of atomsthat atoms combined to make compounds
7 History - Dalton B. Dalton’s Atomic Theory - 1803 1. All matter is composed of small particles which cannot be broken down(atoms) same as Democritus2. All atoms of the same element are identical in size, mass and properties. Atoms of different elements are different in size, mass and propertiesSulfurHydrogen3.Atoms of different element combine in simple ratios to make compoundsPbO2H2S4. In chemical reactions, atoms are combined, separated, or rearranged (No atoms are created or destroyed)So at this point, we believe that an atom is like a small solid ball of matter that cannot be split up
8 Dalton's Amendment'sSome parts of Dalton’s theory were wrong: AMENDMENTSatoms are divisible into smaller particles (subatomic particles)atoms of the same element can have different masses (isotopes)Matter can be lost - Nuclear
9 DISCOVORED THE ELECTRON History - ThomsonC. J.J. ThomsonExperimented with cathode raysUsed electric field to show that cathode rays are negatively charged particlesDISCOVORED THE ELECTRONAfter discovery of the proton, Thomson assumed an atom was a mixture of + and – charged particles, all mixed upPlum-Pudding Model+ -
10 History - Rutherford Screen D. Rutherford Gold foil Radioactive source Ernest Rutherford wanted to determine what an atom looked like.Fired (+) charged alpha particles at a very thin piece of gold (Gold foil)Put a screen behind the foil to determine what happens to the raysGold foilScreenRadioactive sourceClick on me!!!Most of the rays went straight through the foilSome rays deflectedA very few rays came straight back
11 History - Rutherford Rutherford explained this by stating that a. Atoms have mostly empty spaceThis is why most rays went straight throughb. There must be a dense positive center to an atomThis is why the positive rays deflected. (Positive rays are repelled by positive charged objects)+RutherfordmodelLater experiments showed that electrons exist in the space between nuclei
13 Subatomic Particles includes all particles inside atom protonelectronneutroncharge on protons and electrons are equal but oppositeto make an atom neutral, need equal numbers of protons and electrons
14 number of protons identifies the atom as a certain element Subatomic Particlesnumber of protons identifies the atom as a certain elementprotons and neutrons are about same sizeelectrons are much smaller
15 Subatomic Particles# protons = atomic number# electrons = # of protons (for now)# neutrons =mass number– atomic number
16 Examplesp n eLi37343Na1123111211Be49454Fe2656263026
17 Give the p, n, and e in a neutral atom of Silver. BELL RINGERGive the p, n, and e in a neutral atom of Silver.
18 p n e Cl Hg Xe X Some more practice 17 17 18 17 201 80 121 80 54 77 54 22222622
19 Structure of the Atom Nucleus: Electron Cloud: contains protons and neutronstakes up very little spaceElectron Cloud:contains electronstakes up most of space
20 History - Bohr E. Bohr - looked at the arrangement of electrons 3 2 1 Electrons exist in definite areas around the nucleusEnergy levelse-e-e-e-Further from the nucleus, an electron has more energyElectrons can gain energy and “jump” to higher levelsnucleusThey can then give off the energy as they jump back downEnergy levels are numbered 1,2,3,4,5,6,7With 1 being closest to the nucleus and having the least amount of energyPlanetary model+All atoms have the same types of energy levels
21 History - Wave Mechanical Model F. Wave Mechanical ModelDr. Wave MechanicalAka – ‘Electron Cloud’Modified Bohr’s modelElectrons are not in circular orbits, but exist in specific spaces around the nucleusnucleusPattern is random, unpredictablemost dense near nucleuslevellevelEnergy levels contain sublevels
23 Electron Location Located in energy levels outside of the nucleus The closer to the nucleus = less energyThe farther away from the nucleus = more energy
24 Electron Location 2n2 Energy level 1 can have - Electrons are located in energy levels or shells. There are a bunch of energy levels and each level can “fit” only a limited number of electrons.2n2Where ‘n’ represents the energy levelEnergy level 1 can have -Energy level 2 can have -Energy level 3 can have -Energy level 4 can have -2 e-8 e-18 e-32 e-
25 Bohr Diagrams Gives the location and the number of the p, n, and e. Draw the Bohr diagram for Oxygen:p=n=88Valence e- = 6
29 The above is an example of a ground state electron configuration (=the configuration on your R.T.’s)
30 Each electron in an atom has its own distinct amount of energy Each electron in an atom has its own distinct amount of energy. Electrons in the first energy level have the lowest potential energy since they are located closest to the nucleus.
31 As an electron gains a specific bunch of energy, the electron “jumps” to a higher energy state (excited state).p=n=10Excited Statee- Configuration for Ne2-7-1p=n=10Ground Statee- Configuration for Ne2-8
32 How is light produced? Gives off Absorbs nrg Releases nrg p= n= 10 p= Excited Statee- Configuration for Ne2-7-1Absorbs nrgp=n=10Releases nrgGives offGround Statee- Configuration for Ne2-8
33 When an electron returns from a higher energy state to a lower energy state, a specific amount of energy is given off --> RELEASED
34 Each element gives off a certain color or spectrum of colors. You can identify unknown elements by the color of light that they give off.Bohr Animation
35 Ions The number of protons never changes in an atom. So far we have only talked about electrically neutral atoms, atoms with no positive or negative charge on them. Atoms, however, can have electrical charges – They can gain/lose e-. Some atoms can either gain or lose electronsThe number of protons never changes in an atom.
36 Ions If an atom gains electrons, the atom becomes negatively charged. If the atom loses electrons, the atom becomes positively charged (because the number of positively charged protons will exceed the number of electrons). An atom that carries an electrical charge is called an ion.
37 Ions Listed below are three forms of hydrogen; 2 ions and the electrically neutral form.H+ : a positivelychargedhydrogen ionH- : a negativelychargedhydrogen ionH : thehydrogen atom
38 Ions H+ : a positively H- : a negatively charged charged hydrogen ion Neither the number of protons nor neutrons changes in any of these ions, therefore both the atomic number and the atomic mass remain the same.H+ : a positivelychargedhydrogen ionH- : a negativelychargedhydrogen ionH : thehydrogen atom
39 Identify the number of subatomic particles in the following ions: A.) Na+ B.) F- C.) O-2pne119812108101010
40 Which is the electron configuration of an atom in the excited state? BELL RINGERWhich is the electron configuration of an atom in the excited state?2-8-22-8-12-7-12-8-3
44 Identify the number of subatomic particles in the following ions: A.) Mg B.) Br- C.) K+pne123519124520361810
45 Draw the Bohr diagram for a F-1 ion. BELL RINGERDraw the Bohr diagram for a F-1 ion.
46 Isotopes atoms of the same element with different numbers of neutrons most elements exist as a mixture of isotopesDisproves Dalton’s theoryWhat do the Carbon isotopes below have in common? What is different about them?
47 How many protons do each of the hydrogen atoms below have? Mass Numbersum of the particles in nucleus= #p + #nThis is a whole number!!!How many protons do each of the hydrogen atoms below have?
49 Relative Atomic Masssince masses of atoms are so small, it is more convenient to use relative atomic masses instead of real massesto set up a scale, we have to pick one atom to be the standardsince 1961, the carbon-12 nuclide is the standard and is assigned a mass of exactly 12 amu (=atomic mass unit)REFERENCE TABLES
50 Relative Atomic Massatomic mass unit (amu)- one is exactly 1/12th of the mass of a carbon-12 atommass of proton= amu = 1 amumass of neutron= amu = 1amumass of electron= amu = 0 amu
51 Average Atomic Massweighted relative atomic masses of the isotopes of each elementeach isotope has a known natural occurrence (percentage of that elements’ atoms)
52 Calculating Average Atomic Mass An element has three main isotopes with the following percent occurances:#1: amu, 90.51%#2: amu, 0.27%#3: amu, 9.22%Find the average atomic mass and determine the element.= amu
53 Calculating Average Atomic Mass Naturally occurring copper consists of:Cu-63Cu-65Actual Mass62.929amu64.927amuPercentAbundanceRelative abundanceRelative Mass69.71% 30.83%.6971.30831.005443.8720.0263.89
54 Calculate the average atomic mass of Sulfur. BELL RINGERIsotopeAMUNatural Abundance32S31.9794.93%33S32.970.76%34S33.974.29%36S35.970.02%Calculate the average atomic mass of Sulfur.32.06 amu
55 Average Atomic MassThere are two isotopes of Silver, Ag-107 and Ag % of the isotopes are Ag-107, what is the average atomic mass of silver?Ag-10752%=5564=Ag-10948%523210796÷100=107.96
60 The energy emitted is in the form of radiant or light energy which corresponds to a bright-line spectrum. Each element has its own signature or bright-line spectrum.
61 There are several kinds of spectra, such as: continuous & bright line. A continuous spectrum is, as the name implies, a parade of all the colors from the deepest red to the ultraviolet - of which the rainbow in the sky is a good example.
62 In the laboratory, a continuous spectrum can be produced by heating a solid - Light from the electric lamp filament, for example, produces such a spectrum.
63 When light emitted by a gas through which an electrical discharge is passing produces a spectrum consisting of a few isolated parallel lines, it is known as a "bright line spectrum"
64 The characteristic color of neon signs is due to bright red and orange lines in its spectrum. The typical color of neon signs is due to the great intensity of the red and orange lines.
65 A group of elements would create a combination of spectral lines Element X3 different electron jumpsElement YElements X and Y combinedNotice how the combination of X and Y is just a combination of the individual spectral lines?
66 Some Atomic Emission Spectra HydrogenMercuryArgonHelium
67 It should be carefully noted that each element always gives the same pattern of lines. Each element, so to speak, has its own fingerprints, possessed by no other element. This fact is utilized in chemical analysis and in many other applied fields.
68 Identify the number of electrons and neutrons in the following: BELL RINGERIdentify the number of electrons and neutrons in the following:Ti +3S-2
70 Atomic History DEMOCRITUS named the most basic particle atom- means “indivisible
71 Atomic HistoryDALTONAtoms of same element have the same size, mass, and propertiesAtoms can’t be subdivided, created or destroyedAtoms of different element combine in whole number ratios to make compoundsIn chemical reactions, atoms are combined, separated, and rearranged.
72 Atomic History DALTON Some parts of Dalton’s theory were wrong: atoms are divisible into smaller particles (subatomic particles)atoms of the same element can have different masses (isotopes)Most important parts of atomic theory:all matter is made of atomsatoms of different elements have different properties
73 Atomic History RUTHERFORD ‘Gold Foil Experiment’ Atom is mostly empty spaceSmall, hard, dense positive part = NUCLEUS
80 Get the formula from Reference Tables BELL RINGERHow much heat energy in joules is released by 25.0 grams of water when it is cooled from 75.2ºC to 31.9 ºC?Get the formula from Reference Tablesq = mcΔTq = 25.0g (4.18J/g•ºC) 43.3ºCq = 4525 J