Question

Astatine is below iodine in Group VII in the Periodic Table. Which of the following describes the properties of astatine?
(A) State at room temperature - gas, reactivity - displaces chlorine, bromine and iodine
(B) State at room temperature - gas, displaces iodine but does not displace chlorine or bromine
(C) State at room temperature - solid, displaces iodine but does not displace chlorine or bromine
(D) State at room temperature - solid, reactivity - does not displace chlorine, bromine or iodine

Answer 1

Hint: Try to recall the properties of elements in the Halogen group and the trends in the characteristics from top to bottom in a group to answer the question. In the above question, we need only two characteristics, state of matter and reactivity.

Complete step-by-step answer:
We will try to understand the characteristics of elements of group VII in the periodic table. Group VII is also referred to as the Halogen group because of the elements present in the group.
-Halogens are very reactive in their respective period as they need only 1 electron to gain stable configuration. However, this statement holds good only till Iodine as Astatine is a radioactive element.
-Reactivity decreases down the group. This is because as we move down the group, electron affinity decreases due to the large size of the atom. Hence Astatine is the least reactive and cannot displace chlorine bromine or iodine.
-Fluorine and chlorine are in gaseous state and bromine is a liquid at room temperature. However, Iodine is a solid at room temperature, Since Astatine is below Iodine it exists as a solid as well at room temperature.

Therefore, the correct answer is option (D).

Note: Do not consider the terms reactivity and radioactivity to be the same. Along with that also remember that an element that is radioactive need not be highly reactive, for e.g. Astatine, which has very low reactivity.