Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
CHEM 1301 FALL 2003 TEST 1 VERSION 1 NO CHEATING! BUBBLE IN “1” IN THE P COLUMN TO GET YOUR GRADE POSTED!!!!! [the only way you’ll find out how you did!] 1. The Ancient Greeks believed in four elements. One of these "elements" today is known to be a homogeneous mixture. Which is it? (A) air 2. Which of the following formulas represents an element? (A) Bo 3. Which of the following is incorrectly named as a law or theory? (A) (B) (C) (D) (E) The theory of evolution that states that man is descended from apes. Parkinson's Law that states that work expands to fill the allotted time. Boyle's Law that states that the volume and pressure of a gas are inversely proportional VSEPR Law that states that shape of a molecule is due to electrons repelling each other All of these are correctly named as a law or a theory. 4. Which of these statements is a consequence (follows from) the Law of Definite Proportion (composition)? (A) (B) All samples of chlorine contain the two isotopes, 35Cl and 37Cl, in the same ratio. The mass of oxygen that is combined with a fixed mass of nitrogen in compounds containing only nitrogen and oxygen can be expressed as a ratio of nice numbers. The atomic masses of all of the elements in the periodic table have fixed values. The % by mass of lead in the compound, lead sulfide, is the same for all pure samples of lead sulfide obtained from any source. The total mass of substances present after a chemical change is the same as the total mass of substances present before the change. (C) (D) (E) (B) (B) earth HI (C) (C) silver (D) fire (E) water BO3 (D) O2 (E) H2O 1 5. Which of the following statements about Rutherford's experiment is false? (A) (B) (C) (D) (E) Alpha particles were used as they are positive. The particles were fired at a piece of aluminum foil. Most of the particles passed through the foil, indicating that most of the atoms were empty space. A very few particles bounced back, indicating the presence of a small, massive, positive nucleus. One of Rutherford's assistants was Hans Geiger, who later invented the Geiger counter for detecting radioactivity. 6. Which assumption of Dalton’s atomic theory had to be revised or discarded because of the discovery of electrons? (A) (B) (C) (D) (E) The ultimate particles of matter are the atoms of elements, which are indivisible and indestructible. All the atoms of a given element are alike in all respects. The atoms of different elements differ in one or more properties. Compounds are formed by combination of different kinds of atoms. None of these 7. Under the modern atomic theory, which of the following statements is true? (A) (B) (C) (D) (E) Atoms contain the same number of protons and neutrons. The mass of an atom in amu is approximated as the number of protons plus the number of neutrons present in the nucleus. Atoms can be split into a nucleus and the electrons, but usually the electrons are stuck in the nucleus. Different isotopes of an element contain different numbers of electrons. The three primary sub-atomic particles differ only in their charge. 8. Which statement is true? (A) (B) (C) (D) (E) The elements may be broadly classified as metals, non-metals and noble gases. Elements in a row in the periodic table have similar chemical properties. In the periodic table that we use, the elements are arranged in order of increasing atomic number. Rutherford's scattering experiment proved that all atoms contain electrons. Experiments using the Cathode Ray Tube proved that all atoms contain electrons. 9. Which of the following atoms has a symbol not taken from its English name? (A) iron (B) cobalt (C) phosphorus 2 (D) nickel (E) krypton 10. Which of the statements is true? (A) (D) Neon is a pnictogen Vanadium is a transition metal 11. Which of the following statements is incorrect? (A) (D) Iron is ductile Sulfur is malleable 12. Which of the following symbols represents an atom that contains 24 protons and 26 neutrons? (A) 26 13. Tellurium consists of 3 common isotopes. Half of tellurium atoms have a mass of 127, and another 0.45 of them weigh 128. What is the mass of the remaining isotope? The atomic mass of tellurium is 127.6. (A) 125 14. Boron has an atomic mass of 10.8. There are two isotopes of boron – one contains 5 neutrons and the other contains 6 neutrons in the nucleus. What is the fractional abundance of the first one (the one with 5 neutrons)? (A) 0.2 or 1/5 15. Which of the following are definitely isotopes of each other? 1. 2. 3. 4. a chlorine atom with a mass of 35 a chlorine atom with 18 neutrons in the nucleus an atom with 18 protons and 18 electrons in the nucleus a sulfur atom with a mass of 36 (A) (D) 1 and 2 all of them are isotopes of each other Cr (B) (E) (B) (E) (B) (B) (B) 24 Chloroform is a halogen Flubber is a halogen Selenium is a metalloid Scandium is shiny. Fe (C) 126 (C) 0.25 or 1/4 (C) (B) (E) 50 Cr 129 0.33 or 1/3 (C) Krypton is an alkali metal (C) Calcium conducts electricity (D) (D) (D) 50 Fe 130 (E) 0.5 or 1/2 2 and 3 none of them are isotopes of each other 3 (E) (C) (E) 3 and 4 24 Cr 131 0.8 or 4/5 16. Which of the following statements is incorrect? (A) (C) (E) red light has a shorter wavelength than infrared green light has a higher frequency than blue light radiowaves have a longer wavelength than microwaves 17. A form of light has an energy of 6.75 x 10-24 J. Given that h = 6.63 x 10-34 Js and c = 3.00 x 108 m/s, what is the wavelength of this light? (A) 4.47 x 10-57 m 18. In a simplified and sample version of Bohr's model, an electron in the first orbit has an energy of 5.32 x 10-18 J. If the energy of an electron in the second orbit is 8.24 x 10-18 J, what will be the energy of one form of absorbed light? (A) (B) (C) (D) (E) 1.356 x 10-17 J -2.92 x 10-18 J 4.384 x 10-35 J 2.92 x 10-18 J 2.92 x 10-17 J 19. Which famous person is NOT correctly matched with his nationality? (A) (C) (E) Niels Bohr was Danish John Dalton was British Aristotle was Greek. 20. What is the maximum number of electrons that can be placed in the 6th orbit of an atom? (A) 6 (B) (B) 1.34 x 10-48 m (C) (B) (D) 2.95 x 10-3 m (B) (D) 12 (C) 18 4 ultraviolet has a higher energy than violet light gamma rays are the most energetic form of light (D) 0.0295 m (E) 1.02 x 1010 m Ernest Rutherford was Australian Dmitri Mendeleyev was Russian (D) 36 (E) 72