Q 1 :    

Which of the following acts as a strong reducing agent?
(Atomic number : Ce = 58, Eu = 63, Gd = 64, Lu = 71)                      [2024]

• ${\mathrm{Lu}}^{3+}$

   

• ${\mathrm{Ce}}^{4+}$

   

• ${\mathrm{Gd}}^{3+}$

   

• ${\mathrm{Eu}}^{2+}$

   

Q 2 :    

The number of element from the following that do not belong to lanthanoids is

 

Eu, Cm, Er, Tb, Yb and Lu                                   [2024]

• 5

   

• 1

   

• 3

   

• 4

   

Q 3 :    

The electronic configuration of Einsteinium is

 

(Given atomic number of Einsteinium = 99)                    [2024]

• $\left[\text{Rn}\right] 5f^{12} 6d^0 7s^2$

   

• $\left[\text{Rn}\right] 5f^{11} 6d^0 7s^2$

   

• $\left[\text{Rn}\right] 5f^{13} 6d^0 7s^2$

   

• $\left[\text{Rn}\right] 5f^{10} 6d^0 7s^2$

   

Q 4 :    

Number of colourless lanthanoid ions among the following is _________ .         

 

${\text{Eu}}^{3+}, {\text{Lu}}^{3+}, {\text{Nd}}^{3+}, {\text{La}}^{3+}, {\text{Sm}}^{3+}$                          [2024]