Chem Questions!!? 1. Just after an alpha particle leaves the nucleus, would you expect it to speed up of slow down? Why? 2. When an electron vibrates within an atom does it vibrate within the same orbital or between different orbitals? Why? 3. Which requires more energy: boosting on of lithium's 2s electrons to the 3s orbital, or boosting one of beryllium's 2s electron to the 3s orbital? Why? 4. Which of the following two electron configurations represents a higher energy state? What elements are they? a) 1s^2 2s^2 2p^6 3s^1 3p^0 b) 1s^2 2s^2 2p^6 3s^0 3p^1 Which of the following elements is in an excited state and why? a) 1s^2 2s^1 2p^1 b) 1s^2 2s^1 2p^6 3s^2 c) 1s^2 2s^1 2p^2 any help would be greatly appreciated!! :D

Can you help me answer any of these chemistry questions? The person who can answer the most questions gets best answer. Only the first person who answers the queston can get points for it. 1. Lithium consists primarily of two isotopes with mass numbers 6 and 7, respectively. Write the nuclear symbols for each of these isotopes. Given the average atomic molar mass of lithium (see periodic table). which of the lithium isotopes predominates in nature? Explain. 2. Gold-198 is a beta producer with a half-life of 2.7 days that has been used as an implant for cancer therapy. For an implant containing 50 g of Au-198, approximately how much Au-198 remains after 1 week? 3. Explain what it means for an atom to be in an excited state and what it means for an atom to be in its ground state. How does an excited atom return to its ground state? What is a photon? How is the wavelength (color) of light related to the energy of the photons being emitted by an atom? How is the energy of the photons being emitted by an atom related to the energy changes taking place within the atom? 4. Do atoms in excited states emit radiation randomly, at any wavelength? Why? What does it mean to say that the hydrogen atom has only certain discrete energy levels available? How do we know this? What does it mean to say that the energy levels of an atom are quantized? 5. What do the principal energy levels and their sublevels represent for a hydrogen atom? How do we designate specific principal energy levels and sublevels in hydrogen? Describe the sublevels and orbitals that constitute the second principal energy level of hydrogen. How are the individual orbitals in these sublevels designated? 6. List the order in which the orbitals are filled as the atoms beyond hydrogen are built up. How many electrons overall can be accommodated in the first and second principal energy levels? How many electrons can be placed in a given s subshell? In a given p subshell? In a specific p orbital? Why do we assign unpaired electrons in the 2p orbitals of carbon, nitrogen and oxygen? 7. Define the valence electrons in an atom. Define the core electrons in an atom. Why are the valence electrons more important to the atom's chemical properties than the core electrons? How is the number of valence electrons in an atom related to the atom's position on the periodic table? What evidence convinces us that the 4s subshell fills before the 3d subshell? 8. What bond angle results when there are only two valence electron pairs around an atom? What bond angle results when there are three valence pairs? What bond angle results when there are four pairs of valence electrons around the central atom in a molecule? Give examples of molecules containing these bond angles. 9. How do we predict the geometric structure of a molecule whose Lewis structure indicates that the molecule contains a double or triple bond? Give an example of such a molecule, write its Lewis structure, and show how the geometric shape is derived. 10. Write Lewis electron structures for each of the following molecules or ions, and use the VSEPR theory to predict their geometric shapes. If resonance is possible for any of the molecules or ions, draw all likely resonance structures. a. GeC4 b. NO3 c. SO4-2 d. SO3-2 e. SO2 f. O2 g. O3 h. CH3NH2 i. C2H6 j. C2H4 k. BF3 l. BeF2 m. NO2- n. PF3 o. N2H4 11. Describe some of the physical properties of water. Why is water one of the most important substances on earth? 12. Define the normal boiling point of water. Why does a sample of boiling water remain at the same temperature until all the water has been boiled? Define the normal freezing point of water. Sketch a representation of a heating/cooling curve for water, marking clearly the normal freezing and boiling points. 13. Are changes in state physical or chemical changes? Explain. What type of forces must be overcome to melt or vaporize a substance (are these forces intramolecular or intermolecular)? Define the molar heat of fusion and molar heat of vaporization. Why is the molar heat of vaporization of water so much larger than its molar heat of fusion? Why does the boiling point of a liquid vary with altitude? 14. What is a Dipole-dipole attraction? How do the strengths of dipole-dipole forces compare with the strengths of typical covalent bonds? What is hydrogen bonding? What conditions are necessary for hydrogen bonding to exist in a substance or mixture? What experimental evidence do we have for hydrogen bonding? 15. Define dispersion forces. Are London forces relatively strong or relatively weak? Explain. Although London forces exist among all molecules, for what type of molecule are they the only major intermolecular force? 16. Why does the process of vaporization require an input of energy? Why is it so important that water has a large heat of vaporization? Define the equilibrium vapor pressure of a liquid. Describe how this pressure arises in a closed container. How is the magnitude of a liquid's vapor pressure re 17. Define a crystalline solid. Describe in detail some important types of crystalline solids and name a substance that is an example of each type of solid. Explain how the particles are held together in each type of solid (the interparticle forces that exist). 18. Define a solution. Describe how an ionic solute such as NaCl dissolves in water to form a solution. How are the strong bonding forces in a crystal of ionic solute overcome? Why do the ions in a solution not attract each other so strongly as to reconstitute the ionic solute? How does a molecular solid such as sugar dissolve in water'? What forces between water molecules and the molecules of a molecular solid may help the solute dissolve? Why do some substances not dissolve in water at all? 19. Define a saturated solution. Does saturated mean the same thing as saying the solution is concentrated? Explain. Why does a solute dissolve only to a particular extent in water? How does formation of a saturated solution represent an equilibrium'? 20. A solution of 7.50 g of a nonvolatile compound in 22.0 g of water boils at 100.78oC. What is the molecular mass of the solute? 21. The freezing point of water is lowered to -0.390oC when 3.90 g of a nonvolatile molecular solute is dissolved in 475 g of water. Calculate the molar mass of the solute. 22. What is the freezing point of a solution of 12.0 g of carbon tetrachloride dissolved in 750 g of benzene? freezing point of benzene is 5.48oC, kb= 2.53oC.kg/mol. 23. What is the freezing point of these solutions? a. 1.40 mol of Na2SO4 in 1750 g of water b. 0.60 mol of MgSO4 in 1300 g of water 24. What is the molar mass of a compound if 4.80 g of the compound dissolved in 22.0 g of water gives a solution that freezes at -2.50oC? 25. What is the molality of a solution containing 100.0 g of C2H6O2 in 150 g of water? What is the boiling point of this solution? What is the freezing point of this solution?

I have those questions about Chemistry.please help me to answer them.thank you so much? 1. (Points: 2.5) Which of the following elements has atoms of the greatest size (atomic diameter). a. Fluorine b. Potassium c. Calcium d. Chlorine Save Answer 2. (Points: 2.5) What did the Bohr model of the Hydrogen atom best illustrate? a. Nothing b. The orbitals depicting the different energy levels of the Hydrogen atom. c. The seperation in distance between the different orbitals. Save Answer 3. (Points: 2.5) How many 4p electrons does a Bromine atom contain? a. None b. 6 c. 5 d. 2 Save Answer 4. (Points: 2.5) What is the electron configuration for Calcium? a. 1s2, 2s2, 2p6, 3s2, 3p6, 4s2 b. [Ar], 4s2 c. Both 1 and 2 above d. 1s2, 2s2, 2p2, 3s2, 3d10, 3p6, 4s2 Save Answer 5. (Points: 2.5) A figure which illustrates the position of an electron can best be described as a(n): a. Probability map. b. Exact location. c. Model resembling a planet's orbit. d. None of the above. Save Answer 6. (Points: 2.5) An electron occupying which of the following orbitals would represent the lowest energy level? a. 5f 2 b. 3s 2 c. 1s 1 d. 2p 6 Save Answer 7. (Points: 2.5) What type of bond is formed when Carbon combines with Oxygen to form Carbon Monoxide or Carbon Dioxide? a. Ionic b. Polar Covalent c. Covalent Save Answer 8. (Points: 2.5) What type of bond forms between the atoms in a polyatomic ion. a. Ionic b. Covalent Save Answer 9. (Points: 2.5) Atoms of which of the follwing elements are least likely to give up electron(s) to atoms of other elements that it combines with? a. Oxygen b. Fluorine c. Potassium d. Sodium Save Answer 10. (Points: 2.5) Atoms of which of the follwing elements are least likely to give up electron(s) when they form ions? a. Oxygen b. Chlorine c. Potassium d. Sodium Save Answer 11. (Points: 2.5) When a non metal is involved in a chemical reaction, the electron configuration of the ion that forms will mimic the electron configuration of which noble gas. (Octet Rule) a. The noble gas that comes immediately after it on the periodic table. b. The noble gas that comes immediately before it on the periodic table. c. The one before and the one after are equally likely. d. Neither are likely Save Answer 12. (Points: 2.5) Ions formed by which of the following elements will not mimic the Neon noble gas electron configuration by gaining or losing valence electrons? (Octet Rule) a. Fluorine b. Chlorine c. Oxygen d. Magnesium Save Answer 13. (Points: 2.5) Which noble gas configuration does the Iodine mimic by gaining or losing electrons? a. Neon b. Argon c. Krypton d. Xenon Save Answer 14. (Points: 2.5) Which noble gas electron configuration does Calcium mimic by gaining or losing electrons to for an ion? a. Helium b. Neon c. Argon d. Xenon Save Answer 15. (Points: 2.5) True or False: Some oxidation-reduction reactions can also be classified as combustion reactions. a. True b. False Save Answer 16. (Points: 2.5) Which of the following is not an indication that a reaction has occurred? a. The formation of a gas. b. An explosion. c. A precipitate forms. d. It will seperate into 2 layers of different densities. Save Answer 17. (Points: 2.5) Which of the following pairs of reactants will produce a precipitate when combined ina chemical reaction? a. Hydrochloric Acid and Sodium Hydroxide. b. Silver Nitrate and Potassium Cloride. c. Ammonium Sulfate and Magnesium Chloride. d. Magnesium metal and Nitric Acid. Save Answer 18. (Points: 2.5) In which type of reaction are the products always water and a salt? a. Acid-Base b. Precipitation c. Combustion d. Oxidation-Reduction Save Answer 19. (Points: 2.5) A car rusting would be classified as which type of reaction? a. Decomposition b. Oxidation-reduction. c. Acid-Base d. Precipitation Save Answer 20. (Points: 2.5) What is the empirical formula for Acetylene (C2H2) a. C2H6 b. CH c. CH3 d. CH2 Save Answer 21. (Points: 2.5) A compound having the empirical formula of CH4O has a molar mass of 192g./mole. Using the relationship n(empirical formula) = molecular formala, what is the value of n? a. 1 b. 3 c. 4 d. 6 Save Answer 22. (Points: 2.5) How many atoms are in 58.69 g. of Nickel? a. 6.02 x 10*23 b. 1.204 x 10*24 c. 1 d. 59 Save Answer 23. (Points: 2.5) Which of the following contains the greatest number of atoms? a. 147 g. of Sulfuric Acid b. 54 mL of water c. 66 g. of Carbon Dioxide d. 200 g. of Lead Save Answer 24. (Points: 2.5) Which of the following is not a factor in determining the amount of a product yielded in a chemical reaction? a. Mole ratios (from the balanced equation) b. Moles of reactants present. c. Percent yield d. Amount of limiting reactant present. e. None of the Above Save Answer 25. (Points: 2.5) A 48.62g piece of magnesium is reacted with 500 ml. of 6M Hydrochloric acid which contains 3 moles of HCL to form Hydrogen gas and Magnesium Chloride. Which is the limiting reactant. a. Magnesium b. HCl c. Neither (both will be totally reacted. Save Answer 26. (Points: 2.5) The reaction of 83.78 g of Iron metal with an excess of Oxygen produces 101.2 g. of Iron(II)Oxide, what was the percent yield of this reaction? a. 100% b. 81.1% c. 93.8% d. 87.4% Save Answer 27. (Points: 2.5) Magnesium metal burns brightly in Oxygen to form Magnesium Oxide. How many grams of Magnesium Oxide will be produced when 48.61 g. of magnesium metal is burned in an excess amount of Oxygen gas if there is a 90% yield? a. 120.9 g. b. 80.6 g. c. 40.3 g. d. 72.5 g. Save Answer 28. (Points: 2.5) What product(s) always result from the combustion reaction of a Hydrocarbon? a. A salt and water b. Carbon Dioxide and Water c. Hydrogen Carbonate d. Hydrogen Carbide Save Answer 29. (Points: 2.5) The most electronegative elements are found in which part of the periodic table: a. The upper left corner b. The lower right corner c. The lower left corner d. The upper right corner. Save Answer 30. (Points: 2.5) An Ammonia molecule (NH3) has which of the following geometries? a. Trigonal Planar b. Bent c. Tetrahederal d. Trigonal Pyramidal Save Answer 31. (Points: 2.5) Which of the following molecules would you expect to have a geometry closest to that of a water molecule? a. HCl (Hydrogen Chloride) b. H2S (Hydrogen Sulfide) c. NH3 (Ammonia) d. CH4 (Methane) Save Answer 32. (Points: 2.5) Ammonia gas ( NH3(g) ) when exposed to ultraviolet frequencies of electromagnetic radiation is reacts to form Molecular Hydrogen (H2) and Molecular Nitrogen (N2) by the reaction: 2NH3 (g) + Energy gives 3H2 (g) + N2 (g) How would this particular reaction be classified? a. A precipitation reaction. b. An acid-base reaction. c. A synthesis reaction. d. A decomposition reaction. Save Answer 33. (Points: 2.5) The atoms of some elements (mostly gases) form diatomic molecules such as Oxygen (O2), Nitrogen (N2), Fluorine (F2), Hydrogen (H2), Chlorine (Cl2). What the nature of the bond that holds the 2 atoms (of the same element) that hold the molecule together? a. Ionic b. Polar covalent c. Covalent d. They can be either ionic, polar covalent or covalent. Save Answer 34. (Points: 2.5) Which of the given masses of each of the following substances represents represents the least number of moles? (Fewest particles) a. 66.0 grams of dry ice which is solid Carbon Dioxide CO2 (s) b. 200 grams of Lead (Pb) c. 4.0 grams of Molecular Hydrogen gas H2 (g) d. 27 mL of water. Save Answer 35. (Points: 2.5) Molecular Nitrogen N2 (g) combines with Molecular Iodine I2 (s) to form Nitrogen Triodide NI3 (s). If 6 moles of Molecular Iodine reacts with an excess of Molecular Nitrogen, how many moles of Nitrogen Triodide will be produced? Assume 100% yield. a. 2 b. 3 c. 4 d. 6 Save Answer 36. (Points: 2.5) How does the diameter of the K atom compare to the diameter of the K+ cation? a. The K atom has a larger diameter than the K+ cation. b. The K atom has a smaller diameter than the K+ cation. c. The K atom and the K+ cation have about the same diameter. Save Answer 37. (Points: 2.5) Which of the following quantities represents the greatest number of moles? (The most particles): a. 100 g. of water. b. 20 g. Molecular Hydrogen (H2) gas. c. 100 g. of Methane CH4 d. 200 g. of Silver Chloride (AgCl) Save Answer 38. (Points: 2.5) Cations formed by atoms of which of the following elements are an exception to the octet rule. a. Lithium (Li) b. Beryllium (Be) c. Both Li and Be d. Neither Li or Be Save Answer 39. (Points: 2.5) The presence of a dipole moment in the water molecule contributes to all of the following properties of water except for: a. Most ionic solids (salts) dissolve in water. b. Water has higher melting and boiling points than most other hydrogen compounds. c. Water is transparent in the liquid state. d. The surface tension of water Save Answer 40. (Points: 2.5) What is meant by the ground state of an atom? a. When the atom is located on the Earth's surface. b. When the atom is in it's lowest energy state. c. When it's grounded electrically. d. When it's ionized. Save Answer