Q. Out of three elements P, Q and R having atomic numbers 11,17 and 19 respectively which two elements will show similar properties and why?
Answers
Elements that will have similar properties are P and R with atomic numbers 11 and 19.
●We know that elements with same electronic configuration belongs to same group amd due to their sane group and electronic configuration they show similar properties.
●The electronic configuration of P,Q,and R are as follow:--
i)P(11)=2,8,1
ii)Q(17)=2,8,7
iii)R(19)=2,8,8,1
●Since the outer shell electronic configuration of element P and R are same so they belong to same group.
●As elements of same group have similar properties due to periodicity hence P and R have same properties.
●Properties like bonding sharing ,donation of electrons depend on outer shell configuration and as P and R have only one electron in outer configuration so they can easily donate the electron to get stable configuration hence they show same bonding .
Reactivity of elements:
The property of an element is determined with electronic configuration of the element. The electrons in the last orbital determines the reactivity of the elements.
Electronic configuration of P is:
P(11) = 2, 8, 1
The number of electron in outer most shell is 1
Electronic configuration of Q is:
Q(17) = 2, 8, 7
The number of electron in outer most shell is 7
Electronic configuration of R is
R(19) = 2, 8, 8, 1
The number of electron in outer most shell is 1
Since, P and R have same number of electron in their outermost shell. They exhibit similar chemical properties as they belong to same group.