Element Families of the Periodic Table

2023-10-15 10:14| 来源: 网络整理| 查看: 265

01 of 10 Element Families

Element families are indicated by numbers located at the top of the periodic table.

Todd Helmenstine

An element family is a set of elements sharing common properties. Elements are classified into families because the three main categories of elements (metals, nonmetals, and semimetals) are very broad. The characteristics of the elements in these families are determined primarily by the number of electrons in the outer energy shell. Element groups, on the other hand, are collections of elements categorized according to similar properties. Because element properties are largely determined by the behavior of valence electrons, families and groups may be the same. However, there are different ways of categorizing elements into families. Many chemists and chemistry textbooks recognize five main families:

5 Element Families Alkali metalsAlkaline earth metalsTransition metalsHalogensNoble gases 9 Element Families

Another common method of categorization recognizes nine element families:

Alkali Metals: Group 1 (IA) - 1 valence electronAlkaline Earth Metals: Group 2 (IIA) - 2 valence electronsTransition Metals: Groups 3-12 - d and f block metals have 2 valence electronsBoron Group or Earth Metals: Group 13 (IIIA) - 3 valence electronsCarbon Group or Tetrels: - Group 14 (IVA) - 4 valence electronsNitrogen Group or Pnictogens: - Group 15 (VA) - 5 valence electronsOxygen Group or Chalcogens: - Group 16 (VIA) - 6 valence electronsHalogens: - Group 17 (VIIA) - 7 valence electronsNoble Gases: - Group 18 (VIIIA) - 8 valence electrons Recognizing Families on the Periodic Table

Columns of the periodic table typically mark groups or families. Three systems have been used to number families and groups:

The older IUPAC system used Roman numerals together with letters to distinguish between the left (A) and right (B) side of the periodic table. The CAS system used letters to differentiate main group (A) and transition (B) elements. The modern IUPAC system uses Arabic numbers 1-18, simply numbering the columns of the periodic table from left to right.

Many periodic tables include both Roman and Arabic numbers. The Arabic numbering system is the most widely accepted today.

02 of 10 Alkali Metals or Group 1 Family of Elements

The highlighted elements of the periodic table belong to the alkali metal element family.

Todd Helmenstine

The alkali metals are recognized as a group and family of elements. These elements are metals. Sodium and potassium are examples of elements in this family. Hydrogen is not considered an alkali metal because the gas does not exhibit the typical properties of the group. However, under the right conditions of temperature and pressure, hydrogen can be an alkali metal.

Group 1 or IAAlkali Metals1 valence electronSoft metallic solidsShiny, lustrousHigh thermal and electrical conductivityLow densities, increasing with atomic massRelatively low melting points, decreasing with atomic massVigorous exothermic reaction with water to produce hydrogen gas and an alkali metal hydroxide solutionIonize to lose their electron, so the ion has a +1 charge 03 of 10 Alkaline Earth Metals or Group 2 Family of Elements

The highlighted elements of this periodic table belong to the alkaline earth element family. Todd Helmenstine

The alkaline earth metals or simply alkaline earths are recognized as an important group and family of elements. These elements are metals. Examples include calcium and magnesium.

Group 2 or IIAAlkaline Earth Metals (Alkaline Earths)2 valence electronsMetallic solids, harder than the alkali metalsShiny, lustrous, oxidize easilyHigh thermal and electrical conductivityMore dense than the alkali metalsHigher melting points than alkali metalsExothermic reaction with water, increasing as you move down the group; beryllium does not react with water; magnesium reacts only with steamIonize to lose their valence electrons, so the ion has a +2 charge 04 of 10 Transition Metals Element Family

The highlighted elements of this periodic table belong to the transition metal element family. The lanthanide and actinide series below the body of the periodic table are transition metals, too. Todd Helmenstine

The largest family of elements consists of transition metals. The center of the periodic table contains the transition metals, plus the two rows below the body of the table (lanthanides and actinides) are special transition metals.

Groups 3-12Transition Metals or Transition ElementsThe d and f block metals have 2 valence electronsHard metallic solidsShiny, lustrousHigh thermal and electrical conductivityDenseHigh melting pointsLarge atoms exhibit a range of oxidation states 05 of 10 Boron Group or Earth Metal Family of Elements The boron family on the periodic table

These are the elements belonging to the boron family. Todd Helmenstine

The boron group or earth metal family is not as well-known as some of the other element families.

Group 13 or IIIABoron Group or Earth Metals3 valence electronsDiverse properties, intermediate between those of metals and nonmetalsBest-known member: aluminum 06 of 10 Carbon Group or Tetrels Family of Elements

The highlighted elements belong the carbon family of elements. These elements are collectively known as the tetrels. Todd Helmenstine

The carbon group is made up of elements called tetrels, which refers to their ability to carry a charge of 4.

Group 14 or IVACarbon Group or Tetrels4 valence electronsDiverse properties, intermediate between those of metals and nonmetalsBest-known member: carbon, which commonly forms 4 bonds 07 of 10 Nitrogen Group or Pnictogens Family of Elements The nitrogen family of elements

The highlighted elements belong to the nitrogen family. These elements are collectively known as pnictogens. Todd Helmenstine

The pnictogens or nitrogen group is a significant element family.

Group 15 or VANitrogen Group or Pnictogens5 valence electronsDiverse properties, intermediate between those of metals and nonmetalsBest-known member: nitrogen 08 of 10 Oxygen Group or Chalcogens Family of Elements The oxygen family of elements

The highlighted elements belong to the oxygen family. These elements are called chalcogens. Todd Helmenstine

The chalcogens family is also known as the oxygen group.

Group 16 or VIAOxygen Group or Chalcogens6 valence electronsDiverse properties, changing from nonmetallic to metallic as you move down the familyBest-known member: oxygen 09 of 10 Halogen Family of Elements

The highlighted elements of this periodic table belong to the halogen element family. Todd Helmenstine

The halogen family is a group of reactive nonmetals.

Group 17 or VIIAHalogens7 valence electronsReactive nonmetalsMelting points and boiling points increase with increasing atomic numberHigh electron affinitiesChange state as it moves down the family, with fluorine and chlorine existing as gases at room temperature while bromine is a liquid and iodine is a solid 10 of 10 Noble Gas Element Family

The highlighted elements of this periodic table belong to the noble gas element family. Todd Helmenstine

The noble gases are a family of nonreactive nonmetals. Examples include helium and argon.

Group 18 or VIIIA Noble Gases or Inert Gases 8 valence electrons Typically exist as monatomic gases, although these elements do (rarely) form compounds Stable electron octet makes nonreactive (inert) under ordinary circumstances Sources Fluck, E. "New Notations in the Periodic Table." Pure Appl. Chem. IUPAC. 60 (3): 431–436. 1988. doi:10.1351/pac198860030431 Leigh, G. J. Nomenclature of Inorganic Chemistry: Recommendations. Blackwell Science, 1990, Hoboken, N.J. Scerri, E. R. The periodic table, its story and its significance. Oxford University Press, 2007, Oxford.

【本文地址】

公司简介

联系我们