Chemistry
Period 3 Elements
Period 3 elements refer to the elements found in the third row of the periodic table. These elements include sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, and argon. They exhibit a wide range of properties, from metals to nonmetals, and their electron configurations follow the pattern of filling the 3s and 3p orbitals.
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12 Key excerpts on "Period 3 Elements"
- Christopher R. Hren, John T. Moore, Peter J. Mikulecky(Authors)
- 2022(Publication Date)
- For Dummies(Publisher)
Chapter 6 “The Electron”).Take a look at your new friend, the periodic table, in Figure 5-1 . Notice the horizontal rows and the vertical columns of elements:- Periods: The periodic table is composed of horizontal rows called periods. The periods are numbered 1 through 7 on the left-hand side of the table. The atomic numbers increase from left to right in each period. Even though they’re in the same period, these elements have chemical properties that are not all that similar. Consider the first two members of period 3: sodium (Na) and magnesium (Mg). In reactions, they both tend to lose electrons (after all, they are metals), but sodium loses one electron, whereas magnesium loses two. Chlorine (Cl), down near the end of the period, tends to gain an electron (it’s a nonmetal).
- Groups: The vertical columns are called groups , or families . The families may be labeled at the top of the columns in one of two ways. The older method uses Roman numerals and letters. Many chemists (especially old ones like me) prefer and still use this method. The newer method simply uses the numbers 1 through 18 (Figure 5-1 shows both systems of numbering). The older method is usually used in describing the features of the table because it helps relate the position of an element on the periodic table with its number of valence electrons more than the 1–18 grouping system does.
The members of a family do have similar properties. Consider the IA family, starting with lithium (Li) — don’t worry about hydrogen, because it’s unique and doesn’t really fit anywhere — and going through francium (Fr). All these elements tend to lose only one electron in reactions. And all the members of the VIIA family tend to gain one electron. The elements within any group have very similar properties. The properties of the elements emerge mostly from their different numbers of protons and electrons (see Chapter 4
eBook - PDF- William R. Robinson, Edward J. Neth, Paul Flowers, Klaus Theopold, Richard Langley(Authors)
- 2016(Publication Date)
- Openstax(Publisher)
The entering electron does not experience as much repulsion and the chlorine atom accepts an additional electron more readily. Figure 3.36 This version of the periodic table displays the electron affinity values (in kJ/mol) for selected elements. The properties discussed in this section (size of atoms and ions, effective nuclear charge, ionization energies, and electron affinities) are central to understanding chemical reactivity. For example, because fluorine has an energetically favorable EA and a large energy barrier to ionization (IE), it is much easier to form fluorine anions than cations. Metallic properties including conductivity and malleability (the ability to be formed into sheets) depend on having electrons that can be removed easily. Thus, metallic character increases as we move down a group and decreases across a period in the same trend observed for atomic size because it is easier to remove an electron that is farther away from the nucleus. 3.6 The Periodic Table By the end of this section, you will be able to: • State the periodic law and explain the organization of elements in the periodic table • Predict the general properties of elements based on their location within the periodic table • Identify metals, nonmetals, and metalloids by their properties and/or location on the periodic table As early chemists worked to purify ores and discovered more elements, they realized that various elements could be grouped together by their similar chemical behaviors. One such grouping includes lithium (Li), sodium (Na), and potassium (K): These elements all are shiny, conduct heat and electricity well, and have similar chemical properties. A second grouping includes calcium (Ca), strontium (Sr), and barium (Ba), which also are shiny, good conductors of Chapter 3 | Electronic Structure and Periodic Properties of Elements 165 heat and electricity, and have chemical properties in common.
eBook - PDF- C N R Rao(Author)
- 2009(Publication Date)
- World Scientific(Publisher)
Remember that the core electrons do not determine the chemical properties of elements. They are determined by the electrons in the outermost shell (valence electrons). Elements and the periodic table 117 How is the 4 th period different? This is the first period in which the elements are in the s, d and p-blocks. The elements Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn in this period are called transition elements . Transition elements: In these elements, the 3d gets filled after 4s. That is, 4s comes after 3p, not 3d. How does the periodic table help to predict chemical properties? Let us first examine the variation in the properties of the elements across periods. The 3 rd period is the best to illustrate the variations across a period. noble gas From element 11 to 17, there is a change from metallic to non-metallic nature. Ar • Na Mg Al • form basic oxides. • form chlorides with high melting points. • chlorides are electrolytes. • form compounds with anions. • Si P S Cl • form acidic oxides. • form chlorides with low melting points. • chlorides are non-electrolytes. • form compounds with cations. Metallic Elements Non-metallic Elements 3 rd period 11 Na 12 Mg 13 Al metallic 14 Si 15 P 16 S 17 Cl 18 Ar non-metallic 118 Understanding Chemistry The d-block elements in the 5 th and the 6 th periods are also the transition elements. Here, 4 d (or 5 d ) gets filled before 4 p (5 p ). Elements in a group: Groups are chemical families. Remember the alkalis, halogens and noble gases ! Elements in a group • have the same number of valence electrons. • have similar properties. • become more metallic in character down the group. In water solution, most ions of transition elements are coloured. Some of these elements exhibit more than one valency (Fe 2+ , Fe 3+ ; Mn 2+ , Mn 3+ , Mn 4+ ,…, Mn 7+ ). Some of the metals and their ions have catalytic properties. Iron, cobalt and nickel are magnetic. These are permanent magnets ( ferromagnetic ).
eBook - PDF- Amos Turk(Author)
- 2013(Publication Date)
- Academic Press(Publisher)
4 3 • 3.3 C H E M I C A L P E R I O D I C I T Y B E F O R E M E N D E L E E V 3.3 • CHEMICAL PERIODICITY BEFORE MENDELEEV Elements can be grouped by properties into various classes or families, somewhat as living things are classified by biologists. For example, the metals iron, copper, and lead differ as a class from the nonmetals sul-fur, phosphorus, and carbon. Within the metallic class, copper, silver, and gold (coinage metals) differ as a group from calcium, strontium, and barium (alkaline earth metals). These facts suggest that atoms are themselves aggregates of other fundamental entities, a notion that foreshadowed more refined concepts of atomic structure. Hence, the effort of chemists to set up rational systems for classifying the elements was one of the necessary first steps leading to our current progress in understanding the complexities of the atom. Like other fundamental scientific concepts, the idea of chemical periodicity developed at an accelerating rate from quite unsophisticated begin-nings to its current status as a very broad conceptual system. The first modern classification systems were based on relating chemical prop-erties (especially valence) to the atomic weights of the elements; such systems therefore could not be formulated until methods for deter-mining valences and atomic weights began to become available in the early part of the nineteenth century. In 1829, Johann Wolfgang Dobereiner reported several instances in which elements with closely related chemical properties, when arranged in order of atomic weight, showed approximately constant increments of atomic weight. These groups consisted of three elements each, and he therefore called them Examples are given in Table 3.2.
- Barron's Educational Series, Albert S. Tarendash(Authors)
- 2021(Publication Date)
- Barrons Educational Services(Publisher)
Elements within a group share similar properties, and this likeness is directly related to the similarities in the electron configurations of their valence levels. For this reason, we also call a group a chemical family. For example, the elements in Group 13 constitute a chemical family: Atoms of Group 13 elements each have three valence electrons. Consequently, the properties of the elements in this group are similar to one another. (We note, however, that the word similar does not mean “identical”!) 9.4 PROPERTIES ASSOCIATED WITH PERIODICITY Before we describe periodic properties in detail, we need to discuss a number of important factors associated with periodicity. Metallic Character Approximately two-thirds of the elements in the Periodic Table are metals. Metallic elements have certain unique properties: Luster, the mirrorlike shine that reflects light well. Conductivity, the ability to transfer heat and electrons well. Malleability, the ability to be rolled or hammered into thin sheets. Ductility, the ability to be drawn into wire. Examples of metals are sodium (Na), iron (Fe), and mercury (Hg, a liquid at room temperature). In contrast, nonmetals tend to be brittle (in the solid phase), to lack luster, and to have poor conductivities. Examples of nonmetals include sulfur (S), helium (He), and bromine (Br 2, a liquid at room temperature). The bold zigzag line in the Periodic Table separates the metallic elements from the nonmetallic elements. We will refer to it as the metal-nonmetal line. A number of elements, such as boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellerium (Te), have properties somewhat between those of metals and those of nonmetals
eBook - PDFThe History and Use of Our Earth's Chemical Elements
A Reference Guide
- Robert E. Krebs(Author)
- 2006(Publication Date)
- Greenwood(Publisher)
t h r e e The Periodic Table of the Chemical Elements History Without a doubt, the periodic table of the chemical elements is the most elegant organiza- tional chart ever devised. Conceptually, many individuals recognized that certain chemical ele- ments have similar characteristics to other chemical elements before the table was developed. This was accepted even though the atoms of a particular element are different from atoms of related elements. How do we determine what the relationships of these similar characteristics are when compared with different elements? The periodic table of the chemical elements is organized as a matrix of rows of horizontal “periods” that list the elements in their increasing atomic numbers and, generally, according to their atomic weights. For instance, the fourth row in the table is period 4 and starts with group 1 or (1A) element 19 K (potassium with 19 protons in is nucleus) and continues through element 36 Kr (krypton with 36 protons in its nucleus) in group 18 or (VIIIA). (There are two different numbering systems used for identifying the groups in the table. This is explained in the section on the periodic table.) Historically, the elements in periods 2 and 4 were identified as repeating their characteristics after eight elements, each increasing in their atomic weights, thus forming a new period. This was known as the “octet rule.” The matrix also includes vertical columns in which elements are arranged somewhat according to similarities between their chemical and physical properties and those properties of the elements located just above and below them in the column, or “group.” Thus, the three somewhat similar elements in a group might be thought of as a “triad.” A number of prominent chemists of the late nineteenth and early twentieth centuries con- tributed to the development of the periodic table of the chemical elements. These scientists arranged, listed, and categorized various chemicals according to observed properties.
eBook - PDFChemistry for Today
General, Organic, and Biochemistry
- Spencer Seager, Michael Slabaugh, Maren Hansen, , Spencer Seager, Spencer Seager, Michael Slabaugh, Maren Hansen(Authors)
- 2021(Publication Date)
- Cengage Learning EMEA(Publisher)
In magnesium atoms (Mg), the electronic structure is [Ne]3s 2 , and we see that the outermost electron is still in the third shell. In aluminum atoms (Al), the electronic structure is [Ne]3s 2 3p 1 , and we see that, once again, the outermost electron lies in the third shell. In fact, the outermost electrons in all the atoms across period 3 are in the third shell. Copyright 2022 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Electronic Structure and the Periodic Law 89 Because all these electrons are in the same third shell, they should all be the same dis- tance from the nucleus, and the atoms should all be the same size. However, each time an- other electron is added to the third shell of these elements and another positively charged proton is added to the nucleus. Thus, in sodium atoms there are 11 positive nuclear charges attracting the electrons, but in aluminum atoms there are 13. The effect of the increasing nuclear charge attracting electrons in the same shell is to pull all the electrons of the shell closer to the nucleus and cause the atomic radii to decrease as the nuclear charge increases. The chemical reactivity of elements is dependent on the behavior of the electrons of the atoms of the elements, especially the valence electrons. One property that is related to the behavior of the electrons of atoms is the ionization energy. The ionization energy of an element is the energy required to remove an outermost electron from an atom of the element in the gaseous state.
eBook - ePub- (Author)
- 2008(Publication Date)
- Trade Paper Press(Publisher)
Note the plural. There are many different formats, some are three dimensional but all show the elements in order of increasing atomic number. Most have vertical columns called groups and horizontal rows called periods. The underlying reason for the arrangement is the electron arrangement of the atoms of the elements. All elements in the same group have the same number of electrons in the outermost shell which governs the chemical nature of an element, hence their chemical similarity. Elements in the same period have the same number of electron shells, an extra electron being added for each increase in the atomic number.metals and nonmetals
Crossing from left to right elements become more nonmetallic and descending they become more metallic. Thus moving diagonally down to the right, elements are comparable in their metallic/nonmetallic nature. This can be shown by a staircase, or better, as a diagonal line through the boxes of those elements which cannot be clearly classified either as a metal or a nonmetal. For example the use of silicon in computers stems from it being a semiconductor. Metals are conductors, nonmetals are insulators, so semiconductors are both. Science is not black and white but shades of gray.One can copy Mendeleyev’s work by making predictions about “unknown” elements. Knowing that both sodium and potassium react with water producing hydrogen and an alkali, it is reasonable to predict the same behavior for rubidium and cesium directly below them. Since potassium is more reactive than sodium, it is likely that cesium will be the most reactive of the four. It is! When added to a bowl of water it shatters the container! Incidentally cesium is one of three elements which have a different spelling in North America and the UK. Which are the others?are there more elements to discover?
By 1950 all the elements for which Mendeleyev had left gaps had been discovered. Some are extremely rare and were identified from the radioactive decay of other elements, sometimes in the debris of atomic bomb tests (1944–50). However, elements with atomic numbers above 92 have been created by bombarding atoms of uranium with neutrons, carbon nuclei, and other subatomic particles. These synthetic elements are all identified from their radioactivity. As the atomic number increases it becomes harder to make the elements, so less of the element exists… and it is decaying all the time. It is possible to identify 10–18 g but there is less than 1 g of the elements with atomic number greater than 100.
eBook - PDF- Edward J. Neth, Paul Flowers, Klaus Theopold, Richard Langley, William R. Robinson(Authors)
- 2019(Publication Date)
- Openstax(Publisher)
Elements in any one group (or column) have the same number of valence electrons; the alkali metals lithium 3.4 • Electronic Structure of Atoms (Electron Configurations) 139 and sodium each have only one valence electron, the alkaline earth metals beryllium and magnesium each have two, and the halogens fluorine and chlorine each have seven valence electrons. The similarity in chemical properties among elements of the same group occurs because they have the same number of valence electrons. It is the loss, gain, or sharing of valence electrons that defines how elements react. It is important to remember that the periodic table was developed on the basis of the chemical behavior of the elements, well before any idea of their atomic structure was available. Now we can understand why the periodic table has the arrangement it has—the arrangement puts elements whose atoms have the same number of valence electrons in the same group. This arrangement is emphasized in Figure 3.29, which shows in periodic-table form the electron configuration of the last subshell to be filled by the Aufbau principle. The colored sections of Figure 3.29 show the three categories of elements classified by the orbitals being filled: main group, transition, and inner transition elements. These classifications determine which orbitals are counted in the valence shell, or highest energy level orbitals of an atom. 1. Main group elements (sometimes called representative elements) are those in which the last electron added enters an s or a p orbital in the outermost shell, shown in blue and red in Figure 3.29. This category includes all the nonmetallic elements, as well as many metals and the metalloids. The valence electrons for main group elements are those with the highest n level. For example, gallium (Ga, atomic number 31) has the electron configuration [Ar] 4 s 2 3d 10 4 p 1 , which contains three valence electrons (underlined).
eBook - PDF- Morris Hein, Susan Arena, Cary Willard(Authors)
- 2021(Publication Date)
- Wiley(Publisher)
49 stux/7226 images/Pixabay CHAPTER OUTLINE 3.1 Elements 3.2 Introduction to the Periodic Table 3.3 Compounds and Formulas CHAPTER 3 Elements and Compounds In Chapter 1 we learned that matter can be divided into the broad cat- egories of pure substances and mixtures. We further learned that pure substances are either elements or compounds. The chemical elements are very important to us in our daily lives. In tiny amounts they play a large role in our health and metabolism. Metallic elements are used for the skin of airplanes, buildings, and sculpture. For example gold is used in this sculpture of a woman in an English garden. In this chapter we explore the nature of the chemical elements and begin to learn how chemists classify them. Chemists use a shorthand language to represent the chemical ele- ments. Learning chemistry involves learning the symbols chemists use just as learning mathematics requires the use of symbols. In this chapter we begin learning the symbols for the elements and how to read formu- las for compounds. 50 CHAPTER 3 Elements and Compounds 3.1 Elements LEARNING OBJECTIVE: Define an element and write the chemical symbol for an element when given its name. All words in English are formed from an alphabet consisting of only 26 letters. All known sub- stances on Earth—and most probably in the universe, too—are formed from a sort of “chemical alphabet” consisting of over 100 known elements. An element is a fundamental or elementary substance that cannot be broken down by chemical means to simpler substances. Elements are the building blocks of all substances. The elements are numbered in order of increasing com- plexity beginning with hydrogen, number 1. Of the first 92 elements, 88 are known to occur in nature. The other four—technetium (43), promethium (61), astatine (85), and francium (87)— either do not occur in nature or have only transitory existences during radioactive decay.
eBook - PDF- Morris Hein, Susan Arena, Cary Willard(Authors)
- 2016(Publication Date)
- Wiley(Publisher)
The tall columns of the periodic table (1A–7A and the noble gases) are known as the representative elements. Those elements in the center section of the periodic table are called transition elements. A more recent method for labeling the groups on the peri- odic table uses the numbers 1-18. We will show both systems on the periodic tables in this book. FIGURE 3.3 shows these groups on a periodic table. Metals, Nonmetals, and Metalloids The elements can be classified as metals, nonmetals, and metalloids. Most of the elements are metals. We are familiar with them because of their widespread use in tools, construc- tion materials, automobiles, and so on. But nonmetals are equally useful in our everyday life as major components of clothing, food, fuel, glass, plastics, and wood. Metalloids are often used in the electronics industry. The metals are solids at room temperature (mercury is an exception). They have high luster, are good conductors of heat and electricity, are malleable (can be rolled or ham- mered into sheets), and are ductile (can be drawn into wires). Most metals have a high melting point and a high density. Familiar metals are aluminum, chromium, copper, gold, iron, lead, magnesium, mercury, nickel, platinum, silver, tin, and zinc. Less familiar but still important metals are calcium, cobalt, potassium, sodium, uranium, and titanium. Metals have little tendency to combine with each other to form compounds. But many metals readily combine with nonmetals such as chlorine, oxygen, and sulfur to form compounds such as metallic chlorides, oxides, and sulfides. In nature, minerals are composed of the more reactive metals combined with other elements. A few of the less reactive metals such as copper, gold, and silver are sometimes found in a native, or free, state. Metals are often mixed with one another to form homogeneous mixtures of solids called alloys. Some examples are brass, bronze, steel, and coinage metals.
eBook - PDF- Bernard Moody(Author)
- 2013(Publication Date)
- Arnold(Publisher)
A minority of authors prefer to list transitional elements exclusively as B subgroups and therefore the normal elements as A subgroups. Thus Ilia to Vila inclusive become Illb to Vllb respectively and vice versa. However, this is not very important because it is customary to indicate the composition of a family of elements by giving at least the first-named element. Finally, it may be mentioned that some have argued for 18 groups, there being eighteen places (excluding lanthanides and actinides) in the longest periods of the Periodic Table. The construction of the Periodic Table from electronic configurations Hydrogen has the simplest atom, the most abun-dant isotope having a nucleus of one proton with one electron outside it. From this simplest of structures, by the addition at each step of one proton to the nucleus and one external electron, with the appropriate number of neutrons to provide its isotopic mass, the atom of any element may be formed in theory. Chemical character depends on electronic configuration. Periods 1, 2 and 3 The K shell may have one or two electrons only. It is expanded during the formation of atoms of the elements hydrogen and helium, the only members of period 1. Hydrogen, which is quite unlike any other element, has sometimes been placed by itself above the table, or even included above fluorine, F, as well as above lithium, Li. The lithium atom, which has three electrons, has a completed K shell of two and a new shell, L, start-ing with one electron. The elements beryllium to fluorine, of atomic numbers 4-9 inclusive, have progressively extra electrons in the L shell until neon is reached. At this element, both K and L shells are full. The M shell commences with sodium, which has eleven electrons, one more than can be accom-modated in the K and L shells of its atoms. This shell is built up steadily until argon is reached, all elements being placed in the third period. The development of the first three periods is shown in Table 3.6.
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