If last electron enter in p subshell then they are called p block elements. Be and mg do not show flame test due to high value of ionization energy.S block elements show less ionization energy so they show color flame in flame test.Ionic character of metal salt moving down the group increases.Moving down the group metallic bond strength decreases.Melting points and boiling points decreases moving down the group.Moving down the group their density and reactivity will increase.These metals besides for magnesium are stored in oil comparable properties and reactivity tendencies also are observed.These metals have electrons in their valence shell and aside from beryllium can lose this valence electrons to shape an ion with a +2 fee like the alkali metals.Their ionization potential is very low due to formation of inert gas configuration.All metals are soft metal and good conductor of heat and electricity.Volume and mass of the metals are increases when moving down the group.Reactivity of metals are decreases when we moving down the group.

When we go down the group electropositive nature of elements are increases.Ductile nature decreases when we moving down the group.Melting point decreases when we go down the group.

Metallic bond strength moving down the group decreases.1 st group are of alkali metals while 2 nd group are of alkaline earth metals.1 st or 2 nd group are comes in s block.If last electron of element enter in s subshell or orbital called s block element.Modern periodic law:The properties of elements are a periodic function of their atomic numbers, according to modern periodic law. that an element’s atomic number(z) is a more fundamental attribute of an element than its atomic mass. Henry Moseley, an English physicist, established in 1913 A.D.

Metallic elements share some similar properties while nonmetallic elements have their own set of properties.Ītomic number: The number of protons contained in the nucleus of every atom of that element is known as its atomic number.

About 70% percent of the elements are metals, while the remaining 30% are nonmetals.

Elements are Classified Basically Into Three Categories The properties of elements are periodic functions of their atomic masses. Mendeleev’s periodic table (1869): 63 elements were known that time. While similar elements were placed in different slot. Dissimilar elements were placed in same slot. He stated that only 56 elements existed in nature. Limitations– Only calcium showed similarity in qualities according to the law. The attribute of every eighth element (beginning with the first element) repeats if elements are grouped in increasing order of their atomic masses Newland’s law of octaves: till then 56 elements were known that time. Limitations Dobereiner could find only three triads.

When elements are placed in increasing order of their atomic mass in group of three(triads) then the arithmetic mean of mass of 1 st and 3 rd element is found approximate equal to mass of central atom.

Approximately less than 33 elements were known during that time.

Grouping or sorting of elements based on their similarities and differences.

The classification systems help us in grouping the various elements into categories, which we refer to as periods hence the system is also referred to as the periodic classification of elements.

Classification of elements is categorizing the various elements into groups based on similarities and differences in their properties.

In other words, we have classified the elements here.

This is how we organize the elements and this process of categorization helps study the elements with ease. And the arrangement is possible only if we categorize them. So, arranging the various elements is the first step towards understanding their properties.

So, how do we study each element individually for all its properties? It is very difficult to pick every element individually and study all the properties.

Do you know the number of elements astonishingly that number of elements that we find naturally occurring is 98, while the total number of elements known to mankind is 118?.

In nature, elements are the basic forms of every material that we found around, and hence order to study every substance around us, we need to begin with studying various elements.

There are neither proportions nor random mixing of substances so, we can say that mixtures are made up of elements.

They are composed of only the same type of atoms.

These are the purest form of any known substance.

Elements are Classified Basically Into Three Categories.

Periods and groups in periodic table