The position of certain elements in the Modem Periodic Table are shown below:
Using the above table answer the following questions giving reasons in each case:
(i) Which element will form only covalent compounds?
(ii) Which element is a non-metal with valency 2?
(iii) Which element is a metal with valency 2?
(iv) Out of H, C and F which has largest atomic size?
(v) To which family does H, C and F belong?
Answer
(i)
Element E (silicon) belongs to group 14 and period 3.
Electronic configuration of E: 2, 8, 4
Number of Valence electrons = 4
Since it has 4 electrons in its outermost shell , it can neither gain electrons nor lose electrons as it will become unstable.
So, it forms covalent bonds (by sharing electrons).
(ii)
Electronic configuration of B: 2, 8, 6
Number of valence electrons = 6
Valency = 2
Since, B has valency 2, it gains 2 electrons to become stable.
Metals lose electrons to become stable whereas, non-metals gain electrons to become stable.
So, element B(oxygen) is a non-metal with valency 2.
(iii)
Electronic configuration of D: 2, 8, 2
Number of valence electrons = 2
Valency = 2
Since, D has valency 2, it will lose 2 electrons to become stable.
Metals lose electrons to become stable whereas, non-metals gain electrons to become stable.
So, element D(magnesium) is a metal with valency 2.
(iv)
H, C and F all belong to the same group. Element F comes below C and H.
So, element F(argon) has the largest atomic size .
(v)
H, C and F belong to group 18 which means their octet is complete and these elements are stable.
Elements with filled octet belong to the noble gas family.
Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class