Atomic and Ionic Sizes of Lanthanides

Q. The order of stability of the hydrides is as follows:

1. BeH₂ > MgH₂ > CaH₂ > SrH₂ > BaH₂

2. BeH₂ < MgH₂ < CaH₂ < SrH₂ < BaH₂

3. BeH₂ < CaH₂ < MgH₂ < SrH₂ < BaH₂

4. BeH₂ > CaH₂ > MgH₂ > SrH₂> BaH₂

Q. Gradual decrease in atomic and ionic radii from $C{e}^{3+}$ to $L{u}^{3+}$ is called

1. Actinide contraction
2. Lanthanide contraction
3. Both (A) and (B)
4. None of these

Q. Every atom is made of electron, proton and neutron only. So why is everything different color? There must be present inside the electrons, protons and neutrons which gives the atom its color. Am I correct?

Q. Lanthanoid Contraction occurs due to poor shielding by electrons present in f-subshells.

1. False
2. True

Q. among the following the energy of 2s orbital is lowest in Li, Na, H,

Q. In presence of external magnetic field, f orbital is 7 fold degenerate or non degenerate??

Q. Explain electronic configuration of He and N according to Pauli and Hunds principle.

Q. which hs greater +I .-I and +R =OH or OCH3 in bemzene

Q. 40. The number of degenerate orbitals present in an energy level of a H-atom characterized by E = -R/16 where R is the Rydberg constant is: A. 16. B. 9. C. 4. D. 1

Q. Which graph shows the correct trends for the size of $L{n}^{3+}$ ions?

1. 
2. 
3. 
4. 

Q.

In which of the following process the bond order is increased and the magnetic behaviour also changed

1. 

2. 

3. 

4. 

Q. Arrange $C{e}^{+3},L{a}^{+3},P{m}^{+3}$ and $Y{b}^{+3}$ in increasing order of their ionic radii

1. $Y{b}^{+3}<P{m}^{+3}<C{e}^{+3}<L{a}^{+3}$
2. $C{e}^{+3}<Y{b}^{+3}<P{m}^{+3}<L{a}^{+3}$
3. $Y{b}^{+3}<P{m}^{+3}<L{a}^{+3}<C{e}^{+3}$
4. $P{m}^{+3}<L{a}^{+3}<C{e}^{+3}<Y{b}^{+3}$

Q. the corrcect odrder of atomic raddi in group 13 element is

Q. Calculate the number of unpaired electrons in Cu2+ and Cr3+ and compare their magnetic nature.