13.
The chemical property of elements are related to their
Answer : D. valency
14.
The inner transition element among the following is
Answer : B. Lanthanam
15.
The only element which is NOT containing neutrons in its nucleus is
Answer : C. an isotope of hydrogen
16.
The element with the maximum number of stable isotopes in nature is
Answer : B. Tin
17.
Which one of the following is a transition element?
Answer : C. Copper
18.
Element which is an enemy of copper is
Answer : A. sulphur
