División De Educación Preuniversitaria
Teacher Guadalupe González Ochoa
The Periodic Table
Marisol Garcia Gloria
Monday March 7, 2011
← First Aristotle introduced only four element theory: earth, air, fire, and water.
← Then Antoine Lavoisier introduced 33 elements. He also distinguishedbetween metals and nonmetals.
← Jöns Jakob Berzelius introduced letters to symbolize elements and developed a table of atomic weight.
← In 1829 Johann Döbereiner developed “triads”, groups of three elements with similar properties.
← John Newland introduced the “Law of Octaves”.
← Lothar Meyer compiled a periodic table of 56 elements bases of the properties such as molarvolume when arranged in order of atomic weight.
← Dmitri Mendeleev produced a table bases on atomic weights but arranged periodically with elements with similar properties.
← William Ramsay discovered the Noble Gases.
Now the periodic table is arranged in order of increasing atomic number proposed by Henry Moseley.
The purpose of the work is to know on the basic of the periodic table,the groups, the arrangement, and the elements that compose it.
For realize the work, it include the properties of the periodic table, the order of each group and periods. Also it includes each element of the periodic table and its properties. Also I included the characteristics of each group.
In the work, I put the elements by the three different classes: Metals, Nonmetals and Metalloids.It’s easy, to indentify the class of the elements than put the elements in order of increasing atomic number.
The Periodic Table
Henry Moseley arranged the elements in order of increasing atomic number, in the periodic table.
The periodic table is composed by groups and periods.
In groups, the elements have the same number of electrons in their outer orbital, there are eighteen groups.
Inperiods, the elements have the same number of atomic orbital, there are seven periods.
The representative Elements are the elements in an “A” group in the periodic table; these elements display a wide range of physical and chemical properties. In their atoms, the s and p sublevels in the highest occupied energy level and partially filled.
1. Group IA: Alkali Metals
2. GroupIIA: Alkaline Earth Metals
3. Group IIIA
4. Group IVA: The Carbon Family
5. Group VA
6. Group VIA
7. Group VIIA: The Halogens
8. Group VIIIA: The Noble Gases.
The Transition Elements are one of the groups “B” elements in which the highest occupied s sublevels and a nearby d sublevel generally contains electrons. Those d- block elements with a partially filled d sublevelin one of its oxidations states. Those metals never win electrons, only they lose.
The Inner Transition Elements are the elements in lanthanide and actinide series; the highest occupied s sublevel and nearby f sublevel of its atoms generally contain electrons.
The three broad classes of elements are metals, nonmetals and metalloids.
1. Metals are good conductors of heat and electriccurrent; they tend to be ductile, malleable, and shiny.
2. Nonmetals are poor conductors of heat and electric current; they generally have properties opposite of metals.
3. Metalloids tend to have properties that are similar of metals and nonmetals.
Group IA: Alkali Metals
a) The elements of this group are Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), andFrancium (Fr).
b) They have relatively low melting points.
c) There are soft that they can cut with a knife.
d) They react with water.
Group IIA: The Alkaline Earth Metals
a) The elements of this group are Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).
b) They have higher melting points than Alkali Metals.
c) Magnesium is used...