Unit 2 ~ Learning Guide Name: Instructions: Using a pencil, complete the following notes as you work through the related lessons. Show ALL work as is explained in the lessons. You are required to have this package completed BEFORE you write your unit test. Do your best and ask questions if you don t understand anything! History of Elements and Compounds: 1. Write the name and definition of each of the three Fundamental Laws of Chemistry. Law of Definition 2. Write the symbols and names of the first 10 elements discovered. Hint: All discovered B.C. Symbol Name Page 1 of 13
The Periodic Table: 1. Which scientist created the first periodic table and in what year did he do so? 2. Why did his original periodic table have blanks in it? 3. What separates metals from non-metals on the periodic table? 4. Provide names for the following groups on the periodic table Group Name 1 2 17 18 5. Which of these elements is more metallic, Titanium or Iron? Explain how you know this by discussing the position of the elements on the periodic table. 6. Which of these elements, Fluorine or Carbon has a higher electronegativity? Explain how you know this by discussing the position of the elements on the periodic table. Page 2 of 13
Periodic Table Groups 13-16: 1. What two well known materials are allotropes of carbon? 2. Which element makes up 78% of the air we breathe? 3. Which element has an allotrope made from 4 atoms? 4. Which element has an allotrope made from 8 atoms? Atoms, Molecules and Ions Classification Atoms are made of 3 fundamental subatomic particles: protons, neutrons and electrons. The number of protons in a given atom is known as the atomic number and this number can be found on the periodic table. The number of protons and neutrons together is known as the atomic mass. The atomic mass on the periodic table is an average mass of different isotopes and should NOT be used for the following question. The number of electrons in an atom is equal to the number of protons. The charge of an atom is always zero. The charge of an ion is given by # protons - # electrons The full symbol for any given atom will tell you the atomic mass on the top and the atomic number on the bottom. Page 3 of 13
1. Using the information on the previous page and your periodic table, fill in the following chart including BOTH symbol numbers. The first one is done for you. Symbol Atomic Number Atomic Mass p + n o e - charge 2 1H - 1 2 1 1 2-1 a) 231 Ra 0 212 b) Po c) 17 18 0 d) 35 38 0 e) 45 40 0 f) 60 47 0 66 2+ g) Cu 29 29 18 - h) F i) 127 - I 9 53 j) 17 19 18 k) 13 14 10 2. List the diatomic elements & how can you plan to remember them. 3. What are the elements that can be multiatomic? Show them in this form. Page 4 of 13
Isotopes: 1. Put the following words in the correct blanks in the statement below : Mass protons Number neutrons Two isotopes of an element will have the same number of but different numbers of. This means they will have the same Atomic but a different Atomic. 2. a) Calculate the atomic mass of unknown element X given the precise atomic masses and the percent abundance of each isotope of the element X below X-13 12.98504 AMU 78.70% X-15 14.98584 AMU 10.13% X-16 15.98259 AMU 11.17% b) Calculate the approximate atomic mass of potassium given this set of data: K - 39 92.36% K - 40 1.01% K - 41 6.73% Page 5 of 13
3. For the following questions determine the percent abundance of each isotope. The periodic table is NOT needed for these questions and may even confuse you. Ideally you would use the algebra method shown in the course but if you find that confusing you can memorize the following formulas instead. % of smaller isotope = /011 203453 6178795 : 0;53045 /011 /011 203453 6178795:/011 1/02253 6178795 x100% % of larger isotope = 100% - % of smaller isotope a) Oxygen - 16 and Oxygen - 18 with an average atomic mass of 16.2 b) An element has two isotopes 52 X and 54 X, with mass numbers of 52.0 and 54.0 respectively. The relative atomic mass is 53.5. Page 6 of 13
Bohr and Quantum Theory: 1. State the FULL electron configuration of each atom. Be careful with Copper... Element H N P V Cu Br Electron Configuration 2. State the electron configuration of each atom using core notation. Element B S Co I Bi Fr Electron Configuration Page 7 of 13
3. Draw Bohr diagrams for the following chemical species. a) carbon atom b) neon atom c) aluminum atom d) calcium ion (Ca 2+ ) Lewis Diagrams: 1. Define valence electrons? 2. Explain how you can determine the number of valence electrons an element has? Page 8 of 13
3. Give the name and number of valence electrons for each of the following elements Element Symbol Be Ar Mn Na Br Sb Element Name Number of valence electrons 4. Draw Lewis Diagrams for the following atoms and indicate the number of bonding electrons, number of lone pairs, expected number of covalent bonds each would make and the combining capacity. Bromine Hydrogen Nitrogen Lewis Diagram # Bonding Electrons # Lone Pairs # Covalent Bonds Combining Capacity Page 9 of 13
5. Draw Lewis diagrams & structural diagrams (no electrons) of the following molecules. For the last 3, the first element should be in the center with the other elements arranged around it. Molecule Br 2 HCl N 2 Lewis Diagram Structural Diagram Molecule CO 2 NI 3 CH 2 ClF Lewis Diagram Structural Diagram Page 10 of 13
Answers: Atoms, Molecules and Isotopes Classification 1. Symbol Atomic Number Atomic Mass p + n o e - charge 2 1H - 1 2 1 1 2-1 a) 231 88 Ra 88 231 88 143 88 0 b) 212 84 Po 84 212 84 128 84 0 c) 35 17 Cl 17 35 17 18 17 0 d) 73 35 Br 35 73 35 38 35 0 e) 85 40 Zr 40 85 40 45 40 0 f) 107 47 Ag 47 107 47 60 47 0 g) 66 Cu 2+ 29 66 29 37 27 +2 29 h) 18-9 F 9 18 9 9 10-1 i) 127-53 I 53 127 53 74 54-1 j) 36-17 Cl 17 36 17 19 18-1 k) 27 Al 3+ 13 27 13 14 10 +3 13 Isotopes: 2 a) 13.52 AMU b) 39.2 AMU Page 11 of 13
3 a) 16 O = 90% 18 O = 10% b) 54 X = 75% 52 X = 25% Bohr and Quantum Theory 1. Element Electron Configuration H 1s 1 N 1s 2 2s 2 2p 3 P 1s 2 2s 2 2p 6 3s 2 3p 3 V 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 3 Cu 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 10 Br 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 2. Element Electron Configuration B [He] 2s 2 2p 1 S [Ne] 3s 2 3p 4 Co [Ar]4s 2 3d 7 I [Kr]5s 2 4d 10 5p 5 Bi [Xe]6s 2 4f 14 5d 10 6p 3 Fr [Rn]7s 1 Page 12 of 13
3. a) carbon atom b) neon atom --- 4 e- --- --- 8 e- --- --- 2 e- --- --- 2 e- --- 6 p+ 10 p+ c) aluminum atom d) calcium ion (Ca 2+ ) --- 3 e- --- --- 8 e- --- --- 8 e- --- --- 8 e- --- --- 2 e- --- --- 2 e- --- 13 p+ 20 p+ Lewis Diagrams 3. 2, 8, 2, 1, 7, 5 4. Bromine Hydrogen Nitrogen Lewis Diagram H # Bonding Electrons 1 1 3 # Lone Pairs 3 0 1 # Covalent Bonds 1 1 3 Combining Capacity -1 +1 or -1-3 Page 13 of 13