1. Write the complete symbol and determine the no. of electrons, protons and neutrons of the following e- p+ n a.) Oxygen - 8 8 b.) Cesium - 55 55 c.) Argon - 18 18 d.) Uranium - 92 92 e.) Copper - 29 29
2. Calculate the atomic mass of sulfur from its natural isotope. f.) Sulfur-36 g.) Sulfur-32 h.) Sulfur-33 i.) Sulfur-34
3. Complete this table. Symbol of Elements | Atomic Number | Atomic Mass | # of protons | # of Electrons | # of Neutrons | Sc | 21 | | 21 | 21 | 24 | Zn | 30 | | 30 | 30 | 34 | Br | 35 | | 35 | 35 | 44 | Ba | 56 | | 56 | 56 | 82 |
4. Fill in the gaps in the following table. Symbol | 102Ru3+ | Se | Os | I | Ce | p+ | 44 | 34 | 76 | 53 | 58 | no | 58 | | | | | e- | 41 | | | | | Net charge | positive | | | | |
5. How does Dalton’s atomic theory account for the fact that when 1.000 g of water is decomposed into its elements, 0.111 g of hydrogen and 0.889 g of oxygen are obtained regardless of the source of the water? *Using Dalton's theory, it is said that he atoms of elements combine in constant ratios to form compounds. Regardless of the water source, when the water was decomposed to its elements, there is really a constant ratio between the two elements composing the water. 6. Summarize the evidence used by J.J Thomson to argue that cathode rays consist of negatively charged particles? * After observing that the beam of light in the cathode ray tube is attracted to a positive charge and repelled by a negative charge, it is concluded that the rays consist of a stream of small, electrically negatively charged particles. *The cathode rays were deflected from their straight line path by both electric and magnetic fields. The direction of deflection also shows that they are negatively charged particles. 7. a.) What is the purpose of the X-ray source in the Millikan oil-drop experiment. *