Atomic+Structure

Topic 2: Atomic Structure 2.1 The Atom (1h) 2.1.1 State the position of protons, neutrons and electrons in the atom **// TOK: //**// None of these particles can be (or ever will be) directly observed. Which ways of knowing do we use to interpret indirect evidence gained through the use of technology? Do we believe or know of their existence? // 2.1.2 State the relative mass and relative charge of protons, electrons and neutrons. The accepted values are: Relative Mass Charge proton 1 +1 neutron 1 0 electron 5x10-4 -1 2.1.3 Define the terms //mass number// (//A//), //atomic number// (//Z//) and //isotopes of an element.// 2.1.4 Deduce the symbol for an isotope given its mass number and atomic number. Use the notation AZX eg 126C. 2.1.5 Calculate the number of protons, electrons and neutrons in atoms and ions from the mass number, atomic number and charge. 2.1.6 Compare the properties of the isotopes of an element Isotopes have the same chemical properties but different physical properties. Examples include 1 2 3 12 14 35 37 1 H, 1 H, 1 H; 6 C, 7 C; 17 Cl 17 Cl. 2.1.7 Discuss the uses of radioisotopes Examples should include 14C in radiocarbon dating, 60Co in radiotherapy and 131I and 125I as medical tracers Aim 7: Students should be aware of the dangers to living things of radioisotopes but also justify their usefulness with the examples above. 2.2 The Mass Spectrometer (1h) 2.1.1 Describe and explain the operation of a mass spectrometer. A simple diagram of a single beam mass spectrometer is required. The following stages of operation should be considered: vaporization, ionization, acceleration, deflection and detection 2.1.2 Describe how the mass spectrometer may be used to determine relative atomic mass using the 12 C scale. 2.1.3 Calculate non-integer relative atomic masses and abundance of isotopes from given data. 2.3 Electron Arrangement (2h) 2.2.1 Describe the electromagnetic spectrum. Students should be ale to identify the ultraviolet, visible and infrared regions and to describe the variation in wavelength, frequency and energy across the spectrum. 2.2.2. Distinguish between a continuous spectrum and a line spectrum 2.2.3 Explain how the lines in the emission spectrum of hydrogen are related to the energy levels of electrons. 2.2.4 Deduce the electron arrangement for atoms and ions up to //Z// = 20 For example, 2.8.7 or 2,8,7 for //Z// = 17.
 * // TOK //****//://** // What is the significance of the model of the atom in different areas of knowledge? Are the models and theories that scientists create accurate descriptions of the natural world or are they primarily useful interpretations for prediction, explanation and control of the natural world? //
 * TOK: ** Infrared and ultraviolet spectroscopy are dependent on technology for their existence. What are the knowledge implications of this?
 * TOK: ** In drawing an atom, we have an image of an invisible world. Which ways of knowing allow us to access the microscopic world?

[|The mass spectrometer]
MOVIES: BOHR MODEL