Study Guide for Atomic Structure Concepts

Atomic Structure: Name: _________________________________ Unit Test Study Guide Period: _______ Date:____________________ Section #1: Atomic Structure Define: Terms & Questions: 1. atom 2. Why is an atom neutral? 3. electron cloud 4. electrons 5. What determines which element an atom is? 6. neutrons 7. atomic number 8. mass number 9. Which equals one amu the mass of one atom of carbon-12, or 1/12 the mass of one atom of carbon-12? 10. hyphen notation Give the number of protons, neutrons, and electrons for the following: 128Te 45Sc 11.21 13. 52 133Cs 108Ag 12. 14. 47 55 Section #2: Ions & Isotopes 1. Describe how cations are formed. 2. Describe how anions are formed. 3. What type of element generally forms cations? 4. How are isotopes of the same element alike, and how are they different? Give the number of protons, neutrons, and electrons for the following: 65Zn2+ 75As3 5. 30 7. 33 243Am6+ 79Se2 6. 8. 34 95 Section #3: Average Atomic Mass 1. Chlorine has two naturally occurring isotopes, Cl-35 and Cl-37. Using the periodic table, determine which of these two isotopes of chlorine is more abundant. 2. There are two naturally occurring isotopes of iron, Fe-55 and Fe-56. In a sample it is found that Fe-55 made up 15% of the sample. Calculate the average atomic mass for iron. Show all work!

Section #4: History of the Atomic Model Identify: Identify the following models of the atom. A.) Billiard Ball Model B.) Plum Pudding Model C.) Rutherford Model D.) Bohr Model E.) Quantum Mechanical Model e- e- e- e- +e- e- + e- + e- e- e- e- e- 5. _____ 1. _____ 3. _____ 2. _____ 4. _____ 6. How did Rutherford s model improve on Thomson s model? 7. According to the current Quantum Model of the atom, describe the movement and location of the electron. Section #5: Quantities of Atoms The Mole Determine the molar mass for the following compounds. 1. CaSO4 2. Cl2 3. H2SO3 4. Au2O Use dimensional analysis to solve the following conversions. Be sure to record answers with the correct number of sig figs and correct units. No dimensional analysis = No Credit! 5. 8.45 x 1023 molecules H2O = ____________ g H2O 6. 5.66 mol Ag = _________________ atoms Ag 7. 6.75 mol calcium = _____________ g C 8. 85.0 g Cl2 gas = _________________ L Cl2 @ STP 9. 12.50 g sulfur = _________________ atoms of sulfur 10. 9.554 g SiO2 = ___________________ mol SiO2

Atomic Structure: Name: _________________________________ Unit Test Study Guide Period: _______ Date:____________________ Section #1: Atomic Structure Define: Terms & Questions: 1. atom the smallest particle of an element that retains the properties of that element 2. Why is an atom neutral? The number of protons (+) and electrons (-) are equal in a neutral atom. 3. electron cloud the area outside of the nucleus containing electrons. 4. electrons negatively charged subatomic particles found outside of the nucleus 5. What determines which element an atom is? the number of protons determines the element 6. neutrons subatomic particle found in the nucleus that carries no charge 7. atomic number equal to the number of protons of an element, (and the number of electrons in a neutral atom) 8. mass number the number of protons plus neutrons is the mass number of an isotope 9. Which equals one amu the mass of one atom of carbon-12, or 1/12 the mass of one atom of carbon-12? 10. hyphen notation the element name or symbol is followed by a hyphen and the mass number of the isotope Give the number of protons, neutrons, and electrons for the following: 128Te 45Sc21 p+, 24 n0, 21 e- 52 p+, 76 n0, 52 e- 13. 11. 21 52 133Cs55 p+, 78 n0, 55 e- 108Ag 47 p+, 61 n0, 47 e- 14. 12. 47 55 Section #2: Ions & Isotopes 1. Describe how cations are formed. electrons are lost giving the ion more positive charges than negative, and an overall positive charge. Describe how anions are formed. electrons are gained giving the ion more negative charges than positive, and an overall negative charge. What type of element generally forms cations? Metals generally form cations by losing electrons. 2. 3. 4. How are isotopes of the same element alike, and how are they different? Isotopes of the same element have the same number of protons, but they have different numbers of neutrons giving them different masses. Give the number of protons, neutrons, and electrons for the following: 65Zn2+30 p+, 35 n0, 28 e- 75As3 33 p+, 42 n0, 36 e- 7. 5. 30 33 243Am6+95 p+, 148 n0, 89 e- 79Se2 34 p+, 45 n0, 36 e- 6. 8. 34 95 Section #3: Average Atomic Mass 1. Chlorine has two naturally occurring isotopes, Cl-35 and Cl-37. Using the periodic table, determine which of these two isotopes of chlorine is more abundant. Cl-35 is most abundant because the average atomic mass is closer to 35. 2. There are two naturally occurring isotopes of iron, Fe-55 and Fe-56. In a sample it is found that Fe-55 made up 15% of the sample. Calculate the average atomic mass for iron. Show all work! AAM = (55 x 0.15) + (56 x 0.85) = 55.85 amu

Section #4: History of the Atomic Model Identify: Identify the following models of the atom. A.) Billiard Ball Model B.) Plum Pudding Model C.) Rutherford Model D.) Bohr Model E.) Quantum Mechanical Model e- e- e- e- +e- e- + e- + e- e- e- e- e- 5. C 1. A 3. D 2. E 4. B 6. How did Rutherford s model improve on Thomson s model? Rutherford s model determined that most of the atom is empty space. He also determined that the positive nucleus is very dense, small, and only takes up a very small amount of the volume of the atom. He described the electrons as circling around the nucleus. 7. According to the current Quantum Model of the atom, describe the movement and location of the electron. In the current Quantum Mechanics Model, the electrons are located in an electron cloud. Within that cloud electrons have a dual-wave particle nature and exist in orbitals, 3-d regions around the nucleus that indicate the probable location of electrons. Section #5: Quantities of Atoms The Mole Determine the molar mass for the following compounds. 1. CaSO4(1 x 40.08) + (1 x 32.07) + (4 x 16.00) = 136.15 g/mol 2. Cl22 x 35.45 = 70.90 g/mol 3. H2SO3(2 x 1.01) + (1 x 32.07) + (3 x 16.00) = 82.09 g/mol 4. Au2O (2 x 197.00) + (1 x 16.00) = 410.00 g/mol Use dimensional analysis to solve the following conversions. Be sure to record answers with the correct number of sig figs and correct units. No dimensional analysis = No Credit! 5. 8.45 x 1023 molecules H2O = ____________ g H2O ?.?? ? ???? ????????? ? ? ??? ??.?? ? ? ??? = ??.? ? ??? ?.??? ? ???? ????????? 6. 5.66 mol Ag = _________________ atoms Ag ?.??? ? ???? ????? ? ??? ?.?? ??? ? = ?.?? ? ???? ????? ?? 7. 6.75 mol calcium = _____________ g Ca ?.?? ??? ? ??.?? ? ? ??? = ??? ? ?? 8. 85.0 g Cl2 gas = _________________ L Cl2 @ STP ??.? ? ? ? ??? ??.?? ? ??.? ? ? ??? = ??.? ? ??? @ ??? 9. 12.50 g sulfur = _________________ atoms of sulfur ?.??? ? ???? ????? ? ??? ??.?? ? ? ? ??? ??.?? ? = ?.??? ? ???? ????? ? 10. 9.554 g SiO2 = ___________________ mol SiO2 ?.??? ? ? ? ??? ??.?? ? = ?.???? ???SiO2