Chapter 2 Atomic Theory A brief history of the atom also with special attention to Dalton, Crookes, Thompson, Millikan, Rutherford and Chadwick Q.1 What is meant by diffusion? Give e.g. Q.2 What is formed when hydrochloric acid and ammonia react? Q.3 Who was the first man to put forward an atomic theory Q.4 What material did Rutherford hit with alpha particles in his famous experiment that led to the discovery of the nucleus? Q.5 What is the mass of a neutron? Q.6 What was Dalton’s theory? Q.7 Who studied the discharge of electricity through gases? Q.8 What are cathode rays? Q.9 Draw a cathode ray tube? Q.10 What name is given to the negative/positive end of a battery? Q.11 Who discovered the electron? Q.12 What does e/m mean? Q.13 Who devised an expt. to measure the charge on the electron? Q.14 What did Thomson’s model of the atom look like? Q.15 Describe Rutherford’s expt. Give his findings. Q.16 Who discovered the proton? Q.17 Who discovered the neutron? Q.18 Describe the expt.that led to the discovery of the neutron? Q.19 What is the mass of the proton/the electron? Q.20 What did Thomson discover about cathode rays? Q.21 What contribution did Stoney make in the discovery of the electron? Q.22 Compare the mass, charge and location of the proton, neutron and electron. Chapter 3: Arrangement of Electrons in an atom 1. Who was the first scientist to give information about the arrangement of electrons in an atom? 2. What is a continuous spectrum/line spectrum? 3. Name two ways in which spectra can be seen. 4. Describe an expt. to investigate the flame colours of different salts. 5. Name two parts of a spectrometer. 6. What colour is emitted by lithium, potassium, barium, strontium, copper and sodium? 7. What salt commonly causes contamination? 8. How do you reduce contamination? 9. What is an energy level? 10. What is a quantum of energy? 11. What is Heisenberg’s Uncertainty Principle? 12. Who worked out the likely probability of finding a particular electron in an atom? (mathematically) 13. What is the shape of an s/p orbital? 14. How many type of p orbital exist? Draw, give letters to label each. 15. What is the ground state of an atom? 16. How do you work out how much energy is emitted when an electron falls back down to the ground state, from its excited state. 17. Give detailed description (using diagrams) of how elements are able to produce their own particular line spectra. 18. What is the Balmer series? 19. What is the definition of an orbital? 20. What did De Broglie say about moving particles? 21. What is an absorption spectrum? Give some of its uses (two) 22. What does LASER stand for? 23. Give another example of a piece of equipment that makes use of electron transitions. What does ‘h’ stand for in the equation relating energy of light and its frequency. 24. Name the instrument used to study emission line spectra? 25. Give another word to explain ‘quantised’, with reference to energy of an electron? 26. E = hf. What does ‘f’ stand for? 27. What electron transitions give rise to lines in the visible spectrum? 28. What is the maximum number of electrons that can occupy energy Level 3? 29 Which of the following orbitals is spherical: ‘s’, ‘p’, ‘d’ or ‘f’ 30. Give the name of two ‘heavy’ metals that might be found by Atomic Absorption Spectrometer in water analysis? **************************** Chapter 4: Periodic Table The Periodic Table – Know the contributions made by Dobereiner (triads), Newlands (octaves), Mendeleev and Mosely.. Know the difference between Atomic number and Relative Atomic Mass, group and period, metals and non-metals and gases. Be familiar with the following groups – alkali metals, alkaline earth metals, halogens and noble gases. Calculation of the relative atomic mass from the percentage isotopes should be practised. 1. Give explanation and example of how Dobereiner and Newlands grouped elements. 2. Why would Newland’s classification not work today? Give the main reason. 3. In what order did Mendeleev arrange elements? 4. Who changed this order? 5. Give three differences between Mendeleev’s table and the modern day one? 6. What is meant by ‘eka silicon’? 7. Who discovered sodium and potassium? 8. What is the Periodic Law? 9. How many (a) electrons (b) neutrons are in 23 + 11Na 10. What is Relative Atomic Mass? 11. What is a Mass Spectrometer used for? (Give 2) 12. Who built the first Mass Spectrometer? 13. Give the Principles behind the operation of the Mass Spectrometer. 14. Name the parts and be able to draw the instrument. 15. What is an isotope? Give an e.g. 16. Calculate the relative atomic mass of an element give its mass and % abundance. 17. Write the electronic configuration of an element.. 18. Write the s,p configuration of an element.. 19. What is the order in which the sub levels are filled? 20. What does isoelectronic mean? 21. What is Pauli’s Exclusion Principle? 22. What is Hund’s Rule? 23. What is the Aufbau Principle? 24. How many electrons can be accommodated in the p orbitals/d orbitals? 25. Why is the arrangement of electrons in potassium 2,8,8,1 and not 2,8,9,? 26. Write the s,p, configuration for Copper and Chromium? What is different about these? DEFINITIONS Chapters 2,3,4. Atom Smallest particle of matter that can exist by itself Matter Anything that occupies space Element Substance made up of one type of atom – can’t be broken into anything simpler by chemical means Molecule Smallest particle of substance that shows properties of that substance Group of atoms chemically joined Isotopes Forms of element with different mass number due to different numbers of neutrons The Mole 1 mole = 1 mole = RMM (relative molecular mass) in grams = Avogadro’s number (6*1023) = 22.4L of any gas at STP [ 273 K and 760mm of Hg ] Avogadro’s Law 1 mole of any gas at STP occupies 22.4 L Atomic Number Number of protons in an atom. Determines what the element is. Mass number Number of Protons + neutrons in an atom Relative Atomic Mass 1. average of the mass numbers of the isotopes of the element. 2. as they occur naturally 3. taking their abundances into account 4. expressed on a scale on which atoms of the carbon 12 isotope have a mass of exactly 12 units. Relative Molecular Mass 1. The sum of the relative atomic masses of all the atoms in a molecule of the compound. 2. The mass of one molecule of that compound compared with one twelfth of the mass of the carbon 12 isotope. 3. Mass of one mole of a compound = Relative Molecular Mass in grams. Energy Level The fixed energy value that an electron in an atom may have. Atomic Orbital The region in space within which there is a high probability of finding an electron. Hund’s Rule of Maximum Multiplicity When 2 or more orbitals of equal energy are available, the electrons occupy them singularly before filling them in pairs. Aufbau Principle Electrons occupy the lowest available energy level. Pauli Exclusion Principle No more than 2 electrons may occupy an orbital and they must have opposite spin. Heisenberg’s Uncertainty Principle The more accurately we know the position of a particle the less accurately we know its velocity.