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🔹 Atomic Structure 🔹UnitElectron Configuration🔹 Periodic Trends 1 Test Review Answer these questions. 1. What particles form the nucleus of an atom? Protons and neutrons 2. List the charges and masses of subatomic particles....

🔹 Atomic Structure 🔹UnitElectron Configuration🔹 Periodic Trends 1 Test Review Answer these questions. 1. What particles form the nucleus of an atom? Protons and neutrons 2. List the charges and masses of subatomic particles. a. Proton, 1 amu, + charge b. Neutron, 1amu, 0 charge c. Electron, 0 amu, - charge 3. Complete this table: Atomic Mass Number of Number of Number of Symbol of Number Number protons neutrons electrons Atom 20 40 20 20 20 Ca 19 39 19 20 19 K 7 13 7 6 7 N 17 35 17 18 17 Cl 35 80 35 45 35 Br 4. Using the periodic table, determine the number of neutrons. Isotope Number of neutrons 16 8O 8 68 31 Ga 37 45 21 Sc 24 5. How do isotopes of Nitrogen 14 and Nitrogen 15 differ? Nitrogen 14 has 7 protons and 7 neutrons while Nitrogen 15 has 7 protons and 8 neutrons. 6. Write in the number of neutrons contained in each of these isotopes of carbon. Since all carbon atoms have 6 protons, the variation in the isotopes comes from the number of neutrons. a. Carbon-10 4 neutrons b. Carbon-11 5 neutrons c. Carbon-12 6 neutrons  7. The element copper is found to contain the naturally occurring isotopes Copper-63 at 69.1% abundance and Copper-65 at 30.9% abundance. Calculate the average atomic mass of copper. 63 𝑥 0. 691 = 43. 533 65 𝑥 0. 309 = 20. 085 Average atomic mass: 63.62 amu 8. What is each vertical column of elements in the periodic table called? A group 9. What is a period on the periodic table? A row 10. What does the letter “p” in the symbol 4p3 indicate? The letter p indicates the orbital shell the electron is in. 11. Which atomic orbital will the next electron go into? 1s2 2s2 2p6 3s2 3p6 The next orbital to fill is the 4s orbital. 12. What is the electron configuration of magnesium? 1s2 2s2 2p6 3s2 13. An element has the following electron configuration: 1s22s22p63s23p64s23d104p5 a. What is the element? Bromine b. How many sublevels does it have? eight c. What is the highest quantum energy level for this element? 4th energy level d. How many total electrons are in the third energy level? 18 electrons 14. Fill in the missing information for the following Electron Configurations. Element: Si Electron configuration 1s2 2s2 2p6 3s2 3p2 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ 1s 2s 2p 3s 3p 4s 3d Energy → Element: V Electron configuration 1s2 2s2 2p6 3s2 3p64s23d3 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ ↑ 1s 2s 2p 3s 3p 4s 3d Energy →  Element Cl Electron configuration: 1s2 2s2 2p6 3s2 3p5 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ 1s 2s 2p 3s 3p 4s 3d Energy → Element Co Electron configuration: 1s2 2s2 2p6 3s2 3p64s23d7 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ ↑ 1s 2s 2p 3s 3p 4s 3d Energy → 15. What is the general trend from left to right across a period and down the group for each of the following: a. atomic radius - decreases across a period due to increasing nuclear charge. Increases down a group due to electron shielding. b. ionization energy - increases across a period because electron shielding stays the same, but outer shells fill. Noble gasses have the highest ionization energy. Decreases down the group due to electron shielding. c. Electronegativity - General trend across the period is to increase until the Noble gas. Noble gasses have no electronegativity because they do not attract electrons. General trend is to decrease down the group because of electron shielding. 16. How does the electron shielding phenomenon affect the atomic radius for elements a. in the same period? No effect across the period because outer electrons are all at the same energy level. The smaller atomic radius is a result of the increased nuclear charge from adding more protons. down a group? Electron shielding screens outer electrons from the attractive force of the nucleus resulting in larger atomic radii moving down the group.  17. For magnesium, there is a large difference between the second and third ionization energies. For aluminum a large difference is between the third and fourth ionization energies. Explain why this is happening. Ionization Energies (kJ/mol) 1st 2nd 3rd 4th Magnesium 737.7 1,450.7 7,732.7 10,542.4 Aluminum 577.5 1,816.7 2,744.8 11,517.0 Magnesium has two electrons in its outer 3s orbital. Once these two electrons are removed, the third electron will be removed from the 2s or 2p orbital, this is closer to the nucleus so it will take more energy to remove it. Aluminum has 3 electrons in its outer level (3s 23p1) the fourth electron will come from the next lowest energy level - from the 2s or 2p orbital. Whenever there is a change in energy levels when removing electrons, there will be a large difference between the ionization energies.