Asses the impact of the development of the electron microscope on our understanding of the cell and it’s role in cell theory. Since the invention of the electron microscope in 1928 scientists have been able to study the ultrastructure of cells‚ that is‚ parts smaller than what can be seen with a light microscope‚ otherwise known as organelles and their functions. Light microscopes had been developed to a point where the quality of the lenses was not limiting the detail in the image‚ the main
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How many lone pairs of electrons are assigned to the sulfur atom in H2S? a) 0 b) 1 c) 2 d) 3 e) 4 2. Which of the following is a correct Lewis structure for nitrous acid‚ HNO2? 3. The central atom in PH3 is surrounded by a) three single bonds and no lone pairs of electrons. b) three single bonds and one lone pair of electrons. c) three single bonds and two lone pairs of electrons. d) two single bonds‚ one double bond‚ and no lone pairs of electrons. e) two single bonds‚ one
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M10/4/CHEMI/HP2/ENG/TZ1/XX/M+ MARKSCHEME May 2010 CHEMISTRY Higher Level Paper 2 18 pages –2– M10/4/CHEMI/HP2/ENG/TZ1/XX/M+ This markscheme is confidential and for the exclusive use of examiners in this examination session. It is the property of the International Baccalaureate and must not be reproduced or distributed to any other person without the authorization of IB Cardiff. –5– Subject Details: M10/4/CHEMI/HP2/ENG/TZ1/XX/M+ Chemistry HL Paper 2 Markscheme
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Periodic Classification of Elements Classification of Elements according to electron configuration ( type of subshell being filled) *valence electrons –outer electrons of atom which are those involved in chemical bonding ; accounts for similarities in chemical behavior among elemens within each of this groups * Representative elements/ Main Group elements * Group 1A-7A * Incompletely filled s/ p subshells * Display a wide range of physical and chemical properties
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Atomic Structure & Electricity 1. Draw an atom with an atomic number of 12. Label the protons‚ neutrons‚ and electrons. Use the periodic table to identify which atom you have drawn. 2. How many valence electrons are present in this atom? 2 3. Would this atom prefer to gain or lose electrons? Why? Lose‚ because the octet rule dictates that if there is less than 4 valance electrons‚ they would prefer to leave the atom. 4. Describe the differences between conductors‚ semiconductors‚ and
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Experiment 3: Electronic structure‚ bonding and shape of some simple inorganic molecules. Introduction: In quantum chemistry‚ electronic structure is the state of motion of electrons in an electrostatic field created by stationary nuclei. The term encompass both the wave functions of the electrons and the energies associated with them. Electronic structure is obtained by solving quantum mechanical equations for the aforementioned clamped-nuclei problem. Electronic structure problem arise from the
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except for noble gases‚ have valence electrons. These electrons are the ones on the outermost shell. All atoms either want to get rid of these electrons or gain enough to make a full shell. Metals‚ which are on the right side of the periodic table‚ have less than 4 valence electrons. This means they want to get rid of those electrons. Nonmetals‚ which are on the left side of the periodic table‚ have more than 4 valence electrons. These atoms want to gain electrons until they have 8‚ which is a full
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E. 13. In which of these pairs of atoms would the bond be the most polar? A. B. C. D. E. 14. The electron dot formula for O2 shows A. a single covalent bond. B. a double covalent bond. C. an ionic bond. D. a total of 8 2 = 16 electron dots. E. a total of 32 electron dots. 15. The electron dot structure for AsCl3 shows A. a total of 84 electron dots. B. three single bonds and 10 lone pairs. C. two single bonds‚ one double bond‚ and 9 lone pairs. D. one single
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cation has fewer electrons than protons. Anions are negatively charged ions. An anion has more electron than protons. The nature and magnitude of charge on ion depend on the position of an element in the periodic table. In forming an ion‚ an atom of a main group element loses gains electrons to obtain the electronic configuration of the noble gas closest to it in the periodic table. This gives the ion on especially stable electronic arrangement with a completely filled shell of electrons; that is‚ the
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Chem 201 /HW#10 Chapter 9 Electronegativity Table: use this table to answer Q [pic] 1. Bromine tends to form a monatomic ion which has the electronic configuration of a noble gas. What is the electron configuration of that noble gas? a. 1s2 2s2 2p6 3s2 3p6 3d10 4p6 b. 1s2 2s2 2p6 3s2 3p6 4p6 4d10 c. 1s2 2s2 2p6 3s2 3p6 4s2 4p6 d. 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 e. 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 2. Which ion of
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