Periodic Table as a source of information about the elements.
It is also called as Periodic Table of Elements, it is a tabular display of the chemical elements, which are arranged by Atomic
Number, Electron Configuration, and chemical properties.
First 94 elements, hydrogen, to Plutonium, all occur naturally. While elements 95 to 118 have only been synthesized in
laboratories, nuclear reactors, nuclear explosion.
Henry Mosely, 1914, states that the properties of elements vary periodically with Atomic number.
Atomic number is equal to the number of protons in the nucleus of an atom. The atomic number is common characteristic of the
element.
The modern periodic table organizes elements in such a way that information about the elements and their compounds are easily
revealed.
The vertical columns of the periodic table, called groups, identify the principal families of elements. Some families has own special
needs. Group 1, alkali metals, group 2 alkaline earth metals, group 17 halogens, group 18 – noble gases. Groups 13 to 16 are
named based on the first element found in their families. The horizontal rows or periods are numbered top to bottom, there are
7 horizontal rows or periods in the periodic table.
The elements are group into blocks or series in the periodic table. On the later grades, you will learn group in blocks. Group 3 and
12 constitutes one block wherein elements in this block are referred as the Transition elements. The lanthanides and actinides
are special series, but also part of transition block. They are also called as the inner transition elements
How are the element arranged in the periodic table of elements?
There are 7 rows of the periodic table which are called as periods.
Elements from the taller columns are called representative elements or main groups of the periodic table. We can use the periodic
table to identify elements as metals, nonmetals, metalloids. The majority of the elements on the left side of the table are metals.
The nonmetals are confined on the right side of the table.
You learned in Grade 7, that the elements along the stair step line are the semimetals. Semimetals have the appearance and
some properties of a metal but behave like a nonmetal in certain instances.
Physical Properties of Metals
Luster
Malleability
Ductility
Conductivity
The most reactive metals will react even with cold water while the least will not react even with acid.
The ease and speed with which a metal reacts with another substance is called Reactivity.
Is the table o f elements important?
The elements on the periodic table is so important in life today, it has helped scientist discover so many big events. The periodic
table helped scientist discover what elements were needed for humans to survive.
Atomic number increases moving from left to right across a period.
Elements toward the left side of a period are metals while those on the right side are non- metals
Moving down a period on the table adds a new electron shell. Each period number indicates