Which Is Another Name for Groups of Elements? Actinides Families Halogens Periods

Learning Objectives

Past the finish 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 inside the periodic table
• Identify metals, nonmetals, and metalloids by their backdrop and/or location on the periodic table

As early on 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 (Chiliad): These elements all are shiny, conduct rut and electricity well, and have similar chemical backdrop. A 2d grouping includes calcium (Ca), strontium (Sr), and barium (Ba), which likewise are shiny, good conductors of rut and electricity, and have chemical properties in common. However, the specific properties of these two groupings are notably dissimilar from each other. For example: Li, Na, and K are much more than reactive than are Ca, Sr, and Ba; Li, Na, and G form compounds with oxygen in a ratio of two of their atoms to one oxygen cantlet, whereas Ca, Sr, and Ba form compounds with one of their atoms to one oxygen atom. Fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) also exhibit similar properties to each other, but these properties are drastically different from those of any of the elements to a higher place.

Dimitri Mendeleev in Russia (1869) and Lothar Meyer in Germany (1870) independently recognized that there was a periodic relationship among the backdrop of the elements known at that fourth dimension. Both published tables with the elements bundled according to increasing atomic mass. But Mendeleev went one step further than Meyer: He used his tabular array to predict the existence of elements that would have the properties similar to aluminum and silicon, but were nonetheless unknown. The discoveries of gallium (1875) and germanium (1886) provided great support for Mendeleev's piece of work. Although Mendeleev and Meyer had a long dispute over priority, Mendeleev's contributions to the development of the periodic table are now more widely recognized (Figure one).

Figure 1. (a) Dimitri Mendeleev is widely credited with creating (b) the first periodic table of the elements. (credit a: modification of work by Serge Lachinov; credit b: modification of piece of work by "Den fjättrade ankan"/Wikimedia Commons)

Past the twentieth century, information technology became apparent that the periodic relationship involved atomic numbers rather than atomic masses. The modern statement of this relationship, the periodic law, is as follows: the properties of the elements are periodic functions of their atomic numbers. A mod periodic table arranges the elements in increasing order of their atomic numbers and groups atoms with similar backdrop in the same vertical column (Figure two). Each box represents an element and contains its atomic number, symbol, average atomic mass, and (sometimes) name. The elements are arranged in seven horizontal rows, called periods or serial, and 18 vertical columns, called groups. Groups are labeled at the meridian of each column. In the United States, the labels traditionally were numerals with capital messages. However, IUPAC recommends that the numbers 1 through eighteen be used, and these labels are more than common. For the table to fit on a single page, parts of 2 of the rows, a total of 14 columns, are usually written below the main body of the tabular array.

Figure 2. Elements in the periodic tabular array are organized co-ordinate to their backdrop.

Many elements differ dramatically in their chemical and physical properties, but some elements are similar in their behaviors. For example, many elements announced shiny, are malleable (able to be plain-featured without breaking) and ductile (can exist fatigued into wires), and behave estrus and electricity well. Other elements are non shiny, malleable, or ductile, and are poor conductors of heat and electricity. We can sort the elements into large classes with common properties: metals (elements that are shiny, malleable, skillful conductors of estrus and electricity—shaded yellow); nonmetals (elements that appear tedious, poor conductors of heat and electricity—shaded green); and metalloids (elements that conduct heat and electricity moderately well, and possess some backdrop of metals and some backdrop of nonmetals—shaded purple).

The elements can also be classified into the main-group elements (or representative elements) in the columns labeled 1, 2, and 13–18; the transition metals in the columns labeled 3–12; and inner transition metals in the two rows at the bottom of the table (the top-row elements are chosen lanthanides and the lesser-row elements are actinides; Figure three). The elements can be subdivided farther past more than specific properties, such every bit the limerick of the compounds they form. For case, the elements in group 1 (the first cavalcade) grade compounds that consist of ane atom of the element and ane atom of hydrogen. These elements (except hydrogen) are known as alkali metals, and they all accept like chemical properties. The elements in group 2 (the second column) form compounds consisting of one atom of the chemical element and ii atoms of hydrogen: These are called alkaline metal earth metals, with like properties among members of that group. Other groups with specific names are the pnictogens (group xv), chalcogens (group 16), halogens (group 17), and the noble gases (group 18, also known every bit inert gases). The groups can besides be referred to by the offset element of the group: For example, the chalcogens tin can be called the oxygen grouping or oxygen family. Hydrogen is a unique, nonmetallic element with properties like to both group 1A and group 7A elements. For that reason, hydrogen may be shown at the top of both groups, or by itself.

Figure iii. The periodic table organizes elements with like properties into groups.

Click on this link to the Royal Society of Chemistry for an interactive periodic table, which yous can use to explore the properties of the elements (includes podcasts and videos of each element). You may also want to try this one from PeriodicTable.com that shows photos of all the elements.

Example 1:Naming Groups of Elements

Atoms of each of the following elements are essential for life. Give the group name for the post-obit elements:

1. chlorine
2. calcium
3. sodium
4. sulfur

Check Your Learning

Give the group proper noun for each of the following elements:

1. krypton
2. selenium
3. barium
4. lithium

In studying the periodic table, you might have noticed something about the diminutive masses of some of the elements. Element 43 (technetium), element 61 (promethium), and most of the elements with atomic number 84 (polonium) and higher accept their diminutive mass given in square brackets. This is done for elements that consist entirely of unstable, radioactive isotopes (you volition learn more than about radioactivity in the nuclear chemical science chapter). An average atomic weight cannot be adamant for these elements because their radioisotopes may vary significantly in relative abundance, depending on the source, or may not fifty-fifty exist in nature. The number in square brackets is the diminutive mass number (and judge atomic mass) of the most stable isotope of that element.

Key Concepts and Summary

The discovery of the periodic recurrence of similar properties amongst the elements led to the formulation of the periodic tabular array, in which the elements are arranged in order of increasing atomic number in rows known as periods and columns known every bit groups. Elements in the same group of the periodic table have like chemical backdrop. Elements tin be classified as metals, metalloids, and nonmetals, or as a master-grouping elements, transition metals, and inner transition metals. Groups are numbered 1–18 from left to right. The elements in group 1 are known as the alkali metals; those in group two are the alkaline globe metals; those in 15 are the pnictogens; those in xvi are the chalcogens; those in 17 are the halogens; and those in 18 are the noble gases.

Exercises

Metallic or Nonmetal?

1. Using the periodic table, classify each of the following elements as a metal or a nonmetal, and so further classify each equally a master-grouping (representative) element, transition metal, or inner transition metal:
   1. uranium
   2. bromine
   3. strontium
   4. neon
   5. gilded
   6. americium
   7. rhodium
   8. sulfur
   9. carbon
   10. potassium
2. Using the periodic tabular array, allocate each of the following elements as a metal or a nonmetal, and and so further classify each as a principal-group (representative) element, transition element, or inner transition metal:
   1. cobalt
   2. europium
   3. iodine
   4. indium
   5. lithium
   6. oxygen
   7. cadmium
   8. terbium
   9. rhenium

Show Answer

i. (a) metallic, inner transition metal; (b) nonmetal, representative chemical element; (c) metallic, representative element; (d) nonmetal, representative element; (e) metal, transition metal; (f) metal, inner transition element; (g) metal, transition metal; (h) nonmetal, representative chemical element; (i) nonmetal, representative chemical element; (j) metal, representative chemical element

Identifying Elements

1. Using the periodic table, identify the lightest member of each of the following groups:
   1. noble gases
   2. alkaline earth metals
   3. alkali metals
   4. chalcogens
2. Using the periodic table, identify the heaviest fellow member of each of the post-obit groups:
   1. alkali metals
   2. chalcogens
   3. noble gases
   4. alkaline globe metals
3. Use the periodic table to give the proper noun and symbol for each of the following elements:
   1. the noble gas in the same flow as germanium
   2. the element of group ii in the same menstruum as selenium
   3. the halogen in the same catamenia equally lithium
   4. the chalcogen in the same period as cadmium
4. Use the periodic table to requite the name and symbol for each of the post-obit elements:
   1. the halogen in the aforementioned period equally the alkali metal with 11 protons
   2. the element of group ii in the aforementioned period with the neutral noble gas with xviii electrons
   3. the noble gas in the same row as an isotope with 30 neutrons and 25 protons
   4. the noble gas in the same menses equally gold
5. Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each.
   1. the alkali metal with 11 protons and a mass number of 23
   2. the noble gas element with and 75 neutrons in its nucleus and 54 electrons in the neutral atom
   3. the isotope with 33 protons and 40 neutrons in its nucleus
   4. the alkaline earth metallic with 88 electrons and 138 neutrons
6. Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each.
   1. the chalcogen with a mass number of 125
   2. the halogen whose longest-lived isotope is radioactive
   3. the noble gas, used in lighting, with 10 electrons and x neutrons
   4. the lightest alkali metal with 3 neutrons

Glossary

actinide:inner transition metal in the bottom of the bottom two rows of the periodic tabular array

alkali metal:element in grouping i

alkaline earth metal:element in group 2

chalcogen:chemical element in group 16

grouping:vertical column of the periodic table

halogen:element in group 17

inert gas:(also, element of group 0) element in grouping 18

inner transition metal:(also, lanthanide or actinide) element in the lesser ii rows; if in the showtime row, as well called lanthanide, of if in the 2d row, also chosen actinide

lanthanide:inner transition metal in the top of the lesser two rows of the periodic table

main-group element:(also, representative element) element in columns ane, 2, and 12–18

metal:chemical element that is shiny, malleable, practiced conductor of heat and electricity

metalloid:element that conducts rut and electricity moderately well, and possesses some properties of metals and some properties of nonmetals

noble gas:(also, inert gas) chemical element in group eighteen

nonmetal:element that appears dull, poor usher of heat and electricity

menstruum:(also, serial) horizontal row of the catamenia table

periodic police:properties of the elements are periodic function of their diminutive numbers.

periodic table:tabular array of the elements that places elements with similar chemical properties close together

pnictogen:element in group 15

representative element:(too, chief-group element) element in columns i, 2, and 12–18

series:(likewise, menses) horizontal row of the period tabular array

transition metal:element in columns 3–11

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Source: https://courses.lumenlearning.com/sanjacinto-atdcoursereview-genchemistry1-1/chapter/the-periodic-table/

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