Chemistry MCQs for NEET — Practice Questions with Answers

(b) Ununtrium for atomic number = 113;  for Z>86 pd.no. =7

     $$\begin{gathered} Ununtrium = {\left[\mathrm{Rn}\right]}^{86} 7s^{2 }, 5f^{14},6d^{10 },7p^1 \\ p‐block \end{gathered}$$

nihonium is  [Rn].5f¹⁴.6d¹⁰.7s².7p¹

(b) Tantalum (Z= 73) is a transition element.

(c)    Period number     Group number      Element

             5                            7                      Tc

             6                           13                      Tl

             6                            5                       Ta

$$\begin{gathered} \left[Xe\right]4f^{14}5d^{1}6s^2 \\ Atomic number =71 Period number =6th Group number = 3rd \end{gathered}$$

(b) Rubidium is most electropositive in nature.

(c)  $$\begin{gathered} \left(a\right) Cr : 4s^{1}3d^s (each d‐orbital has le") \\ \left(b\right) {\mathrm{Fe}}^{3+}: 4{\mathrm{s}}^{0}3{\mathrm{d}}^{\mathrm{s} } (\mathrm{each} \mathrm{d}‐\mathrm{orbital} \mathrm{has} \mathrm{le}") \\ \left(\mathrm{c}\right) {\mathrm{Cu}}^{+}:4{\mathrm{s}}^{0}3{\mathrm{d}}^{10} (\mathrm{each} \mathrm{d}‐\mathrm{orbital} \mathrm{has} 2\mathrm{e}") \end{gathered}$$

(c) "Unununium" At number =111

      It is a transition element. Period number = 7th; Group number = 11

(d) Atomic radius and metallic character decreases from left to right across the period and increases from top to bottom down the group.

(c) P is trivalent non - metal Q is divalent metal hence formula of compound is $P_2{Q}_3$.

(b) Zn is bigger

In (a)  use (z/e) concept for isoelectronic specie.

     In (c) size of neutral atom is greater than its cation.