Which Statement Is True Regarding Main Group Families of the Periodic Table?

Chapter 2. Atoms, Molecules, and Ions

2.5 The Periodic Table

Learning Objectives

By the end of this section, yous will be able to:

• Land the periodic police and explain the arrangement of elements in the periodic tabular array
• Predict the general properties of elements based on their location within the periodic table
• Identify metals, nonmetals, and metalloids past their properties and/or location on the periodic table

As early on chemists worked to purify ores and discovered more elements, they realized that diverse elements could exist grouped together by their similar chemic behaviors. One such grouping includes lithium (Li), sodium (Na), and potassium (K): These elements all are shiny, conduct heat and electricity well, and take similar chemical properties. A 2d group includes calcium (Ca), strontium (Sr), and barium (Ba), which likewise are shiny, good conductors of oestrus and electricity, and take chemical properties in common. However, the specific properties of these two groupings are notably different from each other. For example: Li, Na, and K are much more reactive than are Ca, Sr, and Ba; Li, Na, and Yard class compounds with oxygen in a ratio of two of their atoms to one oxygen atom, whereas Ca, Sr, and Ba form compounds with 1 of their atoms to ane oxygen atom. Fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) besides showroom similar properties to each other, but these properties are drastically different from those of any of the elements above.

Dimitri Mendeleev in Russia (1869) and Lothar Meyer in Germany (1870) independently recognized that there was a periodic human relationship amongst the properties of the elements known at that fourth dimension. Both published tables with the elements arranged according to increasing atomic mass. But Mendeleev went 1 step further than Meyer: He used his tabular array to predict the existence of elements that would have the backdrop similar to aluminum and silicon, merely were yet 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'due south contributions to the development of the periodic table are now more than widely recognized (Figure one).

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

By the twentieth century, it became apparent that the periodic human relationship involved atomic numbers rather than atomic masses. The modern statement of this human relationship, the periodic law, is every bit follows: the backdrop of the elements are periodic functions of their atomic numbers. A modernistic periodic tabular array arranges the elements in increasing order of their atomic numbers and groups atoms with like properties in the same vertical column (Effigy 2). Each box represents an chemical element and contains its atomic number, symbol, average diminutive mass, and (sometimes) proper noun. The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups. Groups are labeled at the acme of each column. In the United states of america, the labels traditionally were numerals with capital messages. However, IUPAC recommends that the numbers one through 18 be used, and these labels are more common. For the table to fit on a single page, parts of two of the rows, a full of 14 columns, are usually written beneath the main torso of the table.

Figure 2. Elements in the periodic table are organized according to their properties.

Many elements differ dramatically in their chemical and physical properties, but some elements are similar in their behaviors. For example, many elements appear shiny, are malleable (able to be plain-featured without breaking) and ductile (can be fatigued into wires), and deport heat and electricity well. Other elements are not shiny, malleable, or ductile, and are poor conductors of heat and electricity. We tin sort the elements into large classes with mutual properties: metals (elements that are shiny, malleable, good conductors of heat and electricity—shaded yellow); nonmetals (elements that appear ho-hum, poor conductors of rut and electricity—shaded green); and metalloids (elements that conduct heat and electricity moderately well, and possess some backdrop of metals and some properties of nonmetals—shaded purple).

The elements tin can too exist classified into the master-group elements (or representative elements) in the columns labeled 1, 2, and 13–18; the transition metals in the columns labeled iii–12; and inner transition metals in the two rows at the bottom of the table (the summit-row elements are called lanthanides and the lesser-row elements are actinides; Effigy 3). The elements can be subdivided further by more specific properties, such as the composition of the compounds they form. For example, the elements in group 1 (the beginning column) form compounds that consist of one cantlet of the chemical element and one atom of hydrogen. These elements (except hydrogen) are known as brine metals, and they all have similar chemical properties. The elements in group 2 (the second column) form compounds consisting of one cantlet of the element and ii atoms of hydrogen: These are chosen alkaline earth metals, with similar properties among members of that grouping. Other groups with specific names are the pnictogens (grouping 15), chalcogens (group sixteen), halogens (group 17), and the noble gases (group eighteen, too known as inert gases). The groups can also be referred to by the first element of the grouping: For instance, the chalcogens can exist called the oxygen grouping or oxygen family unit. Hydrogen is a unique, nonmetallic element with properties similar to both grouping 1A and group 7A elements. For that reason, hydrogen may be shown at the height of both groups, or past itself.

Figure 3. The periodic table organizes elements with similar properties into groups.

Click on this link for an interactive periodic tabular array, which you tin can use to explore the properties of the elements (includes podcasts and videos of each element). You may also want to effort this one that shows photos of all the elements.

Case 1

Naming Groups of Elements
Atoms of each of the following elements are essential for life. Give the group name for the following elements:

(a) chlorine

(b) calcium

(c) sodium

(d) sulfur

Solution
The family names are as follows:

(a) halogen

(b) element of group ii

(c) alkali metallic

(d) chalcogen

Check Your Learning
Give the group name for each of the following elements:

(a) krypton

(b) selenium

(c) barium

(d) lithium

Answer:

(a) noble gas; (b) chalcogen; (c) alkaline world metal; (d) alkali metal

In studying the periodic tabular array, you lot might take noticed something almost the atomic masses of some of the elements. Chemical element 43 (technetium), element 61 (promethium), and nigh of the elements with atomic number 84 (polonium) and higher take their atomic mass given in foursquare brackets. This is done for elements that consist entirely of unstable, radioactive isotopes (you lot volition learn more about radioactivity in the nuclear chemical science affiliate). An average atomic weight cannot exist adamant for these elements considering their radioisotopes may vary significantly in relative abundance, depending on the source, or may not fifty-fifty exist in nature. The number in foursquare brackets is the atomic mass number (and approximate atomic mass) of the near stable isotope of that element.

Cardinal Concepts and Summary

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

Chemistry End of Chapter Exercises

1. Using the periodic table, allocate each of the post-obit elements as a metal or a nonmetal, and so further classify each equally a master-grouping (representative) element, transition metal, or inner transition metal:

   (a) uranium

   (b) bromine

   (c) strontium

   (d) neon

   (east) aureate

   (f) americium

   (1000) rhodium

   (h) sulfur

   (i) carbon

   (j) potassium

2. Using the periodic table, classify each of the following elements as a metal or a nonmetal, so further allocate each as a master-group (representative) element, transition metal, or inner transition metal:

   (a) cobalt

   (b) europium

   (c) iodine

   (d) indium

   (e) lithium

   (f) oxygen

   (h) cadmium

   (i) terbium

   (j) rhenium

3. Using the periodic table, place the lightest member of each of the following groups:

   (a) noble gases

   (b) element of group i world metals

   (c) brine metals

   (d) chalcogens

4. Using the periodic tabular array, identify the heaviest member of each of the following groups:

   (a) alkali metals

   (b) chalcogens

   (c) noble gases

   (d) alkaline earth metals

5. Use the periodic table to requite the name and symbol for each of the following elements:

   (a) the noble gas in the same catamenia equally germanium

   (b) the alkaline earth metal in the aforementioned menstruum as selenium

   (c) the halogen in the aforementioned menstruum as lithium

   (d) the chalcogen in the same menstruation as cadmium

6. Apply the periodic table to give the proper noun and symbol for each of the following elements:>

   (a) the element of group vii in the same menses equally the alkaline with 11 protons

   (b) the alkaline globe metallic in the same flow with the neutral noble gas with 18 electrons

   (c) the noble gas in the same row as an isotope with thirty neutrons and 25 protons

   (d) the noble gas in the same period equally gold

7. Write a symbol for each of the post-obit neutral isotopes. Include the atomic number and mass number for each.

   (a) the alkali metal with 11 protons and a mass number of 23

   (b) the element of group 0 element with 75 neutrons in its nucleus and 54 electrons in the neutral atom

   (c) the isotope with 33 protons and 40 neutrons in its nucleus

   (d) the element of group ii with 88 electrons and 138 neutrons

8. Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each.

   (a) the chalcogen with a mass number of 125

   (b) the halogen whose longest-lived isotope is radioactive

   (c) the noble gas, used in lighting, with 10 electrons and 10 neutrons

   (d) the lightest alkali metal with three neutrons

Glossary

actinide

inner transition metal in the bottom of the bottom two rows of the periodic table

brine metal

element in grouping 1

element of group i globe metal

chemical element in grouping 2

chalcogen

chemical element in group 16

group

vertical column of the periodic table

halogen

element in group 17

inert gas

(likewise, noble gas) element in grouping eighteen

inner transition metallic

(too, lanthanide or actinide) element in the bottom 2 rows; if in the beginning row, likewise called lanthanide, or if in the second row, also called actinide

lanthanide

inner transition metallic in the top of the lesser two rows of the periodic table

master-group element

(also, representative element) element in columns 1, 2, and 12–18

metal

element that is shiny, malleable, adept conductor of estrus and electricity

metalloid

element that conducts heat and electricity moderately well, and possesses some properties of metals and some backdrop of nonmetals

noble gas

(also, inert gas) element in group 18

nonmetal

element that appears dull, poor usher of estrus and electricity

period

(also, serial) horizontal row of the periodic tabular array

periodic police

properties of the elements are periodic function of their atomic numbers.

periodic table

table of the elements that places elements with similar chemical properties close together

pnictogen

element in grouping 15

representative element

(also, main-grouping element) chemical element in columns i, 2, and 12–xviii

series

(also, period) horizontal row of the period tabular array

transition metal

element in columns 3–11

Solutions

Answers to Chemistry Finish of Affiliate Exercises

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

3. (a) He; (b) Be; (c) Li; (d) O

5. (a) krypton, Kr; (b) calcium, Ca; (c) fluorine, F; (d) tellurium, Te

vii. (a) [latex]_{11}^{23}\text{Na}[/latex]; (b) [latex]_{54}^{129}\text{Xe}[/latex]; (c) [latex]_{33}^{73}\text{As}[/latex] ; (d) [latex]_{88}^{226}\text{Ra}[/latex];

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Source: https://opentextbc.ca/chemistry/chapter/2-5-the-periodic-table/

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