The radioactive isotope used in the treatment of cancer is:

Which of the following statement is correct about the atom of and element?

There are two species represented as ³⁵Cl and ³⁷Cl. Which of the following statement is correct regarding these species?

Elements having valency ‘one’ are:

In a sample of ethyl ethanoate (CH₃COOC₂H₂), the two oxygen atoms have the same number of electrons but different number of neutrons. Which of the following is the correct reason for it?