AIEEE 2004 (Chemistry) Mock Test

Cerium ($Z=58$) is an important member of the lanthanoids. Which of the following statements about cerium is incorrect?

Which one of the following has the largest number of isomers?

The correct order of magnetic moments (spin only values in B.M.) among the following is:
(Atomic numbers: $\text{Mn}=25;\text{Fe}=26,\text{Co}=27$)

Consider the following nuclear reactions:${}_{92}^{238}\text{M}\to {}_y^x\text{N}{+}_2^4\text{He}$${}_y^x\text{N}\to {}_B^A\text{L}+2{\beta }^{+}$ The number of neutrons in the element $\text{L}$ is:

The half – life of a radioisotope is four hours. If the initial mass of the isotope was $200\text{g}$, the mass remaining after $24$ hours undecayed is: