The Actinoids

Define actinoid contraction.

There is a gradual decrease in the size of atoms or ${\mathrm{M}}^{3+}$ ions across the series. This may be referred to as the Lanthanoids contraction.

Ionisation enthalpies of actinoids are lower than lanthanoids.

Transuranic elements are elements with atomic no. greater than _____. Americium($\mathrm{Am}$) is an example of a transuranic element.

The magnetic properties of the actinoids are more complex than those of the _____.

Actinoids exhibit larger oxidation states than lanthanides because of the very small energy gap between _____ .

Explain the magnetic properties of actinoids ?

Explain the reasons for variable oxidation state shown by actinoids ?

Explain the variable oxidation states shown by actinoids ?

The actinoid used for the manufacture of fine rods for atomic reactors is _____.

Which of the following ion is colourless?

${\mathrm{U}}^{3+}$ ,${\mathrm{Cm}}^{4+}$ , ${\mathrm{Th}}^{4+}$

Does actinoids show actinoid contraction similar to lanthanoid contraction ?

Which of the following actinoids show oxidation states upto $+7$?

Give an explanation for the gradual decrease in size (actinoid contraction) from element to element is greater among the actinoid than that among the Lanthanoids (lanthanoid contraction).

Differentiate between lantanoids and actinoids.

The extent of actinoid contraction is greater than lanthanoid contraction, explain.

Give four differences of Lanthanoid and Actinoid series.

Most of the radioactive elements are in

The Radioactive element which was discovered by Madam Curie and the name of which is based on her country is