General Properties of Lanthanoids

Identify the following:
An alloy consisting of approximately $95\%$ lanthanoid metal used to produce bullet, shell and lighter flint.

$$\begin{gathered} \underset{\underset{\mathrm{M}=\mathrm{transition} \mathrm{metal}}{(\mathrm{Colourless} \mathrm{liquid})}}{{\mathrm{MCl}}_4}\stackrel{\mathrm{Zn}+{\mathrm{H}}_2\mathrm{O}}{\to }\underset{\left(\mathrm{A}\right)}{\mathrm{Purple} \mathrm{coloured} \mathrm{compound}}. \\ \downarrow \mathrm{moist} \mathrm{air} \\ \left(\mathrm{B}\right) \\ \mathrm{White} \mathrm{fumes}. \end{gathered}$$

Identify ($\mathrm{A}$), ($\mathrm{B}$) and ${\mathrm{MCl}}_4$. Also explain colour difference between ${\mathrm{MCl}}_4$ and ($\mathrm{A}$).

Which of the following pairs has the same size?

Which compound is generally used in making optical glasses such as Crooke's lenses which protect eyes against UV light?

Which element is used in making bone nails for surgery and why?

What are three characteristics of cerium?

How do cerium reacts with oxygen at room temperature?

Discuss some of the properties of cerium.

An element in $+3$ oxidation state has the electronic configuration $\left[\mathrm{Ar}\right] 3{\mathrm{d}}^3$. Its atomic number is

Give explanation

 Europium$\left(\mathrm{II}\right)$ is more stable than cerium$\left(\mathrm{II}\right)$

The pair that has similar atomic radii is:

Why do lanthanoid form coloured compound?

Which financial statement shows the financial performance of a company over a specific period?

Which of the following statements is true regarding the financial statements of a company?

Which method of redemption requires the company to buy back its debentures in the open market?

What is the minimum percentage of the nominal value of debentures that must be transferred to the Debenture Redemption Reserve before redeeming the debentures?

Which of the following is NOT a term associated with the issue of debentures?

What is the term for the value stated on debentures at the time of their issue?

What is the term used when debentures are issued at a value equal to their nominal value?

What is the term used for the value at which debentures are issued when it is below their nominal value?