Topic2-AtomicTheory：主题2原子理论.doc

Topic 2 - Atomic Theory Review Name: _ Period: _10 points 2.1 The atom2.1.1 : State the position of protons, neutrons and electrons in the atom.2.1.2 State the relative masses and relative charges of protons, neutrons and electrons. Protons: Relative mass = 1relative charge = +1 Neutrons: Relative mass = 1 relative charge = 0 Electrons: Relative mass = 5 x 10-4relative charge = -11. Define atomic mass unit, amu: 2. Which of the following has the largest atomic mass?a) Potassiumb) Phosphorusc) Tind) Magnesiumanswer: C3. Sketch an atom of carbon-14. Show positions and numbers of the electrons, protons, and neutrons.2.1.3 Define the terms mass number (A), atomic number (Z) and isotopes of an element. Mass number (A): Number of protons + neutrons. Atomic number (Z): Number of protons. Isotope: Atoms of the same element with same atomic number but different mass numbers because they have different numbers of neutrons.2.1.4 : Write the symbol of an isotope: AZXA = mass number, Z = atomic number, X = atomic symbol.4. Write the symbols for Iodine-131 and Cobalt 60.2.1.5 Calculate the number of protons, neutrons and electrons in atoms and ions from the mass number, atomic number and charge. Number of protons = atomic numberNumber of neutrons = Mass number - atomic numberNumber of electrons = protons + charge for negative ions.Number of electrons = protons - charge for positive ions.5. How many protons, electrons and neutrons are in Carbon-13?How many protons, electrons and neutrons are in sodium-23 ion, Na+?How many protons, electrons and neutrons are in oxide-16 ion, O2-?Write the symbol for each of the particles.6. The species 10444Ru contains:a) 44 neutrons and 44 electronsb) 44 protons and 44 electronsc) 44 protons and 104 neutronsd) 60 neutrons and 60 electronsanswer: B2.1.6 Compare the properties of the isotopes of an element. 1. Isotopes may differ in physical properties such as mass and density.2. They may differ in radioactivity but not generally in chemical properties.3. They will be present in different amounts (abundance).4. They have different number of neutrons. 7. Compare the isotopes of hydrogen to each other: Protium: 11H, deuterium: 21H, and tritium: 31H. How do the isotopes differ? How are they the same?8. A certain element is listed as having an atomic mass of 72.6 units. It is probably true that it contains:a) A mixture of isotopes.b) A mixture or allotropes.c) A mixture of isomers.d) An impurity.Answer: A9. Using the two isotopes of boron, 105B and 115B as your example, explain why:a) These atoms have identical chemical properties even though their masses are different.b) Explain why the relative atomic mass of boron is not a whole number. 2.1.7 Evaluate the uses of radioisotopesExamples should include 14C in radiocarbon dating, 60Co in radiotherapy, and 131I and 125I as medical tracers. 9. Discus the use of the following isotopes, including the issues involved with their use.:Carbon 14Cobalt 60Iodine 131Iodine 1252.2.1 Describe and explain the operation of a mass spectrometer. (VIADD)The stages of operation are: vaporisation, ionisation, acceleration, deflection and detection. The substance to be tested is vaporised (by heat, absence of oxygen) then ionised by electric current. Ions are accelerated through an electric field, then deflected by a magnetic field. Ions are then detected. The angle of deflection reflects their mass to charge ratio.10. Describe how a mass spectrometer works. Be able to draw a labeled diagram, showing all the parts.2.2.2 Describe how the mass spectrometer may be used to determine relative atomic mass using the 12C scale. 2.2.3 Calculate non-integer relative atomic masses and abundance of isotopes from given data. Atomic masses are the average of the atomic mass of each isotope (isotopic mass) times the isotopes relative abundance. This results in non-integer atomic masses.Examples: Chlorine has an atomic mass of 35.5 amu. Chlorine exists largely of 2 different isotopes: 75% 3517Cl and 25% 3717Cl.11. Calculate the relative atomic mass of chlorine is 35.5 amu, using the data above.2.2 Electron Arrangement2.3.1 Describe the electromagnetic spectrum. Be able to identify the ultraviolet, visible and infrared regions, and to describe the variation in wavelength, frequency and energy across the spectrum. Continuous spectrum goes continuously through red, orange, yellow, green, blue, indigo, violet. A line spectrum contains only some individual lines from this spectrum.12. Sketch a continuous spectrum. Compare the wavelengths, frequencies, and energies of each color. Include ultraviolet and infrared wavelengths.2.3.2 Distinguish between a continuous spectrum and a line spectrum. 2.3.3 Explain how the lines in the emission spectrum of hydrogen are related to electron energy levels. Be able to draw an energy level diagram, show transitions between different energy levels and recognize that the lines in a line spectrum are directly related to these differences. A. Electrons are excited by running an electric current through them, by heating them in a flame test, or by shining ultraviolet light on them. B. This energy causes electrons to become excited and to jump into higher electron shells. ( X X* ) C. This state is only temporary, however, and the electron falls back to the lower energy or ground state.D. This change decreases the energy of the electron, and the energy released is emitted in the form of a photon of light.E. If this photon falls into the visible spectrum of light, then it produces a visible emission spectrum. F. For the electrons, which are further away from the nucleus, the electron shells are closer together in terms of space and energy, causing the lines in the emission spectrum to converge towards the end of the spectrum.G. As the atoms of each element have a different electron configuration, each element will produce a different atomic emission spectrum. 13. Which wavelength from the section of the emission spectrum shown for hydrogen has the most energy? The light with a wavelength of 380 nm or the light having a wavelength of 656 nm?14. Sketch the emission spectrum from hydrogen including ultraviolet, visible and infrared regions of the spectrum. Explain the transition in energy levels.2.3.4 Deduce the electron arrangement for atoms and ions up to Z = 20. For example, 2.8.7 or 2,8,7 for Z = 17. The main electron energy levels contain a maximum of: 2, 8, 18, 32 electrons, but as only the first twenty elements are required, then the first electron e