Periodic Table reading

Locate the element titanium (Ti) in the Periodic Table. Read the following paragraph about its chemistry and answer the questions which follow. 

Let us start at an elementary level or with a typically "chemical" view. Suppose we ask an undergraduate chemistry student how quantum mechanics explains the periodic table. If the student has been going to classes and reading her book she will respond that the number of outer-shell electrons determines, broadly speaking, which elements share a common group in the periodic table. The student might possibly also add that the number of outer-shell electrons causes elements to behave in a particular manner. 

Read over the entire laboratory activity. Use the periodic table in your textbook to answer the following questions. 

Morris, Richard. The last sorcerers the path from alchemy to the periodic table. Washington (DC) Joseph Henry P, 2003. xii, 282 p. ISBN 0-309-08905-0 Contents Preface — 1. The four elements — 2. Prelude to the birth of chemistry — 3. The sceptical chymist — 4. The discovery of the elements — 5. A nail for the coffin — 6. "Only an instant to cut off that head" — 7. The atom — 8. Problems with atoms — 9. The periodic law — 10. Deciphering the atom — Epilogue the continuing search — appendix. A catalog of the elements — Further reading — Index... 

Reading the periodic table from left to right, starting at the top and finishing at the bottom, displays tbe filling order and the energy order of the atomic orbitals. 

In this section, you have seen how a theoretical idea, the quantum mechanical model of the atom, explains the experimentally determined structure of the periodic table, and the properties of its elements. Your understanding of the four quantum numbers enabled you to write electron configurations and draw orbital diagrams for atoms of the elements. You also learned how to read the periodic table to deduce the electron configuration of any element. 

Mendeleev s paper did not evoke much interest either when it was published two months later in the journal of the Chemical Society. However, matters were different when Mendeleev published another paper, The Natural System of the Elements, two years later. This paper, which contained a revised periodic table (Mendeleev now listed elements in vertical columns rather than horizontal rows), had a much greater response. Russian chemists read it with great interest, as did foreign chemists when the paper was translated into German the same year. 

The answers to questions like these, favorites of chemistry teachers, are best organized in a table. First, look up the symbols Cl, Os, and K in the periodic table in Chapter 4 and find the names of these elements. Enter what you find in the first column. To fill in the second and third columns (Atomic Number and Mass Number), read the atomic number and mass number from the lower left and upper left of the chemical symbols given in the question. The atomic number equals the number of protons the number of electrons is the same as the number of protons, because elements have zero overall charge. So fill in the proton and electron columns with the same numbers you entered in column two. Last, subtract the atomic number from the mass number to get the number of neutrons, and enter that value in column six. Voila The entire private life of each of these atoms is now laid before you. Your answer should look like the following table. 

When you re given the atomic number, the number of protons, or the number of electrons, you automatically know the other two numbers because they re all equal. Each element in the periodic table is listed with its atomic number, so by locating the element, you can simply read off the atomic number and therefore know the number of protons and electrons. To calculate the atomic mass or the number of neutrons, you must be given one or the other. Calculate atomic mass by adding the number of protons to the number of neutrons. Alternatively, calculate the number of neutrons by subtracting the number of protons from the atomic mass. 

Trying to visualize how electrons fill orbitals can get very confusing, so Figure 4-2 is a periodic table with the different orbitals put in place of the elements. It will help. A lot. To use the diagram, start at the upper left and read from left to right. When you reach the end of a row, go to the beginning of the next row down. Keep going until you reach your element. 

J. Barrett, Atomic Structure and Periodicity, Royal Society of Chemistry, Cambridge, 2001. This book is meant to act as preliminary reading for the present text, but covers the subject matter in a largely non-mathematical way. The theoretical basis of the Periodic Table is dealt with in considerable detail and is followed by discussions of the periodicities of the main physical and chemical properties of the elements. 

As can be seen in Figure 6.20, the farther apart two atoms are in the periodic table, the greater the difference in their electronegativities, and hence the greater the polarity of the bond between them. So a chemist need not even read the electronegativities to predict which bonds are more polar than others. To find out, he or she need only look at the relative positions of the atoms in the periodic table—the farther apart they are, especially when one is at the lower left and one is at the upper right, the greater the polarity of the bond between them. 

Below ore some conclusions that an average general chemistry student (certainly not you ) might have after reading about the periodic table in a general chemistry textbook written by average authors (not us ). Please rewrite each statement to clarify possible misconceptions (if any). 

The 112 known elements—there may be more by the time you read this—combine to form millions of compounds. That is far more than we could study individually. Moreover just learning a string of isolated facts would not build the insight we need to devise new compounds. It is far more useful to study a select group of representative elements and their compounds. In this and the next two chapters, we use the periodic table as our guide in this highly selective journey. The topics of these chapters are commonly called descriptive chemistry—the description of the preparation, properties, and applications of elements and their compounds. 

The greatest advantage of a three-dimensional periodic table is the correct placement of the f elements. In addition, a three-dimensional periodic table is compact and easy to read. A disadvantage of the spiral three-dimensional periodic table is the location of the rows. Since the spiral is continuous, numbers are needed to identify the rows. Also, the elements in a spiral periodic table must be rotated in order see all of them. 

Reading the periodic table takes a little practice. To begin with, each element has its own box with two key numbers. The atomic number of the element, or the number of protons its atoms contain, is at the top of the box. (See the table in the Appendix on pages 92-93.) Below the atomic number is the element s symbol letter or letters. The elements name is printed below the symbol, and underneath the name is the atomic weight. Element boxes on some periodic tables may include only the element symbol and atomic number. 

O alkali metal a reactive metal in Croup I of the Periodic Table alkali metals read with water to produce alkaline solutions... 

The pair of invariants (d nt) plays an important role in connection with the periodic table for benzenoid hydrocarbons (see below). Therefore we give some relations in terms of these invariants. Firstly, the coefficients of C HS read ... 

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