Question

The ground state electronic configurations of the elements, U, V, W, X and Y (these symbols do not have any chemical significance) are as follows:
U $\;1{s^2}2{s^2}2{p^3}$
V $1{s^2}2{s^2}2{p^6}3{s^1}$
W $1{s^2}2{s^2}2{p^6}3{s^2}3{p^2}$
X $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^5}4{s^2}$
Y $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6}$
Determine which sequence of elements satisfy the following statements:
(i) Element forms a carbonate which is not decomposed by heating
(ii) Element is most likely to form coloured ionic compounds
(iii) Element has largest atomic radius
(iv) Element forms only acidic oxide
A) VWYU
B) VXYW
C) VWYX
D) VXWU

Answer 1

‌ As we know that alkali metal elements form different carbonates, d-block elements form various coloured compounds, and group fifteen elements usually forms acidic compounds and down the group acidic character decreases. We also know that noble gases are the only elements which possess complete electronic configuration.

Complete answer:
As we know that the electronic configuration tells us about the element’s atomic number and thus helps in identifying the name of that element. So the first option which is given is having seven electrons and we know that Nitrogen is the element which possesses an atomic number of $7$.
We know that nitrogen forms various acidic oxides by reacting with oxygen and these oxides are mainly nitrogen oxides $(NO)$, Dinitrogen pentoxide $({N_2}{O_5})$, Dinitrogen trioxide $({N_2}{O_3})$ etc. Therefore, the correct match for option U is (iv).
Next we have the electronic configuration showing the atomic number $11$ and we also know that sodium is the element that possess the atomic number $11$. Sodium generally forms a carbonate compound which is sodium carbonate given as $N{a_2}C{O_3}$. Also the sodium carbonate is not decomposed on heating. So the correct option for V is (i).
Then we have the electronic configuration showing the atomic number $14$ and according to periodic table Silicon is the element having atomic number $14$. And down the group atomic radius decreases so silicon has the largest atomic radius. So, the correct match for W is (iii).
Next the atomic number is $25$and the element is Manganese and it is a d-block element and we know that d-block elements are known to form various coloured compounds. Therefore, the correct match for X is (ii).
Lastly we have Y which has atomic number $36$ and the noble gases are the group of elements possessing this stable electronic configuration.
Therefore, the correct sequence is VXWU.
Therefore the correct option is option D..

Note: Always remember that the coloured compounds are formed by the d-block elements which can be blue in colour formed by copper, Manganese forms pink coloured compounds, chromium possess dark green coloured solutions, cobalt usually have deep blue colour and iron shows yellow or brown colour.