There are 7th house on till central Road squad period in period physical and chemical properties change from left to right the period starts from Enfield metals and end with zero groups.<br>

&nbsp;&nbsp;&nbsp; It contain only two elements in this period ke shell is completely filled it is the shortest period with two elements content element l and M are being filled by electron second period is start with a lion and any third period start from sodium in organ organ each of these period content 18th elements 4th period starts from K and ends up with krypton start from R B and ends with at accident it contains two elements it is start from C S and end with rm14 animals are placed at the bottom of periodic table this spot in element are selectively call entry Gates&nbsp; it started with a pen come this period is incomplete 2109 elements have been discovered the period also includes 14 elements call and actinides this period 11019 elements<br>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Vertical column in periodic table are cal group these are the divided into groups a and subgroup be there are 18 in all including translations and inert gases the subgroup and subgroup B are separated so that the elements with similar properties are placed together and can easily be located<br>

&nbsp;The long period are extended and short period broking so as to accommodate the transition elements and at Opera Max 8 place between group 2A and group 3 if the inert gases are located at the extreme right off the table the Lander landed and accidents are group separately and placed at the bottom of the table the position of hydrogen is still and decided some elements which Re symbol in chemical properties are placed in separate group such as facilities in similarities in properties but are placed in separate group according to the according to similarities and dissimilarities