Lanthanoids

Number of paramagnetic ions among the following d- and f-block metal ions is ________.
$\ce{Mn^{2+}}$, $\ce{Cu^{2+}}$, $\ce{Zn^{2+}}$, $\ce{Yb^{2+}}$, $\ce{Sc^{3+}}$, $\ce{La^{3+}}$, $\ce{Gd^{3+}}$, $\ce{Lu^{3+}}$, $\ce{Ti^{4+}}$, $\ce{Ce^{4+}}$
(Atomic number of Mn = 25, Cu = 29, Zn = 30, Yb = 70, Sc = 21, La = 57, Gd = 64, Lu = 71, Ti = 22, Ce = 58)

The correct statements among the following are,

A. Mo(VI) and W(VI) are less stable than Cr(VI).

B. $\ce{Ce^{4+}}$ and $\ce{Tb^{4+}}$ are oxidant while $\ce{Eu^{2+}}$ and $\ce{Yb^{2+}}$ are reductant.

C. Cm and Am have seven unpaired electrons.

D. Actinoid contraction is greater from element to element than lanthanoid contraction.

Choose the correct answer from the options given below:

Pairs of elements with the same number of electrons in their respective 4f orbital are

[Atomic number. Eu-63, Gd-64, Dy-66, Ho-67, Tm-69, Yb-70, Lu-71, Hf-72]

A. (Eu and Gd)

B. (Dy and Ho)

C. (Yb and Hf)

D. (Lu and Tm)

Choose the correct answer from the options given below:

Given below are two statements :

Statement I : The number of pairs among $[\ce{Ti^4+},\ \ce{V^2+}]$, $[\ce{V^2+},\ \ce{Mn^2+}]$, $[\ce{Mn^2+},\ \ce{Fe^3+}]$ and $[\ce{V^2+},\ \ce{Cr^2+}]$ in which both ions are coloured is 3.

Statement II : The number of pairs among $[\ce{La^3+},\ \ce{Yb^2+}]$, $[\ce{Lu^3+},\ \ce{Ce^4+}]$ and $[\ce{Ac^3+},\ \ce{Lr^3+}]$ ions in which both are diamagnetic is 3.

In the light of the above statements, choose the correct from the options given below :

The pair(s) of diamagnetic ions is(are)

Cerium (IV) has a noble gas configuration. Which of the following is correct statement about it ?

The most common oxidation state of Lanthanoid elements is +3. Which of the following is likely to deviate easily from +3 oxidation state?

The 'f' orbitals are half and completely filled, respectively in lanthanide ions

[Given : Atomic no. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66]

Which one of the lanthanoids given below is the most stable in divalent form?

Which of the following pair is not isoelectronic species?

(At. no. Sm, 62; Er, 68; Yb, 70; Lu, 71; Eu, 63; Tb, 65; Tm, 69)