Question

Four elements P, Q , R and S have atomic number 12, 13 ,14 and 15 respectively.
Answer the followings:
i)What is the valency of Q?

ii) Classify this element as metals and nonmetals.

iii) Which two elements have same valency?

Answer 1

Answer:

As its atomic number is 13, its electron distribution pattern is 2,8,3. As it has 3 electrons in its outer most shell, it readily loses them to attain octet. Thus its valency is identified as +3.

Explanation:

The electronic configuration of the element are as follows : <br> p (Z = 12), 2, 8, 2 Q (Z = 13) 2, 8, 3 <br> R (Z = 14) , 2, 8, 4 S (Z = 15) 2, 8, 5 <br> (i) The valency of the element Q is 3 since it has three valence electrons. <br> (ii) The elements P and Q are metals while the elements R and S are non-metals. <br> (iii) The element P will form the most basic oxide of formula PO.

i) 3 (+3)

(ii) P and Q are metals while S is a non-metal, R is a metalloid.

(iii) P (because they are in same period and metallic character decreases in a period due to increase in the nuclear charge).

Answer 2

Answer:

I) 3

ii) P and Q are metals while S is a non-metal, R is a metalloid.

iii) non of the above