(a) why did mendeleev have gaps in his periodoc table (b) staye any thre limitations of mendeleevs classificatio. (c) how does electroni configuration of atoms change in the period within increses in yhe atomic number
Answers
1● he has kept gap in his table for the future elements ... he kept some gap by predicting the existence of some undiscovered elements of that time as only 63 elements were known during that time ..
2● limitations of mendeleev's periodic table are :
■ no fixed position was given to hydrogen because it resembled the properties of alkali metals as well as halogens ..
■ isotopes of elements have different atomic masses .so each of these isotopes should be given different positions .however isotopes being chemically similar should be placed in the same position . Thus isotopes of elements could not be assigned a proper position ..
■ some elements placed in the same sub-groups had different properties . For ex.. manganese was placed with halogens ..
■ mendeleve has broken his own law he place the element with slightly greater atomic mass first and slightly less atomic number element before that ... that were aluminium and silicon , Cobalt and nickel , tellurium and iodine ...
3● as we move from left to right a period the the number of electrons in outer most shell increases ... and as we move from up to down a period the number of shell increases but the number of valence electron remains same ....
HOPE IT WAS HELPFUL PLS MARK ME AS BRAINLIEST ...