Question

Flame test is not given by:
(A) $ Ca $
(B) $ Ba $
(C) $ Be $
(D) $ Li $

Answer 1

Hint: We know that the a flame test is that test in which an element gives the characteristic color to the flame and is not given by the element which belongs to the category of alkaline earth metals and has the atomic number as $ 4 $ and mass number as $ 9 $ and lies in the $ 2nd $ period of the periodic table. Now you can easily answer the given statement.

Complete answer:
First of all let’s discuss what a flame test is. By the flame test, we simply mean the test in which when an element is exposed in the Bunsen flame and gives the characteristic color to the flame. Now consider the statement as; the elements of the group first and group second elements of the periodic table i.e. the alkali metals and bathe alkaline earth metals give characteristic color to the when exposed in the Bunsen flame but beryllium and magnesium of the alkaline earth melts do not give this test. Hence, from above all the mentioned elements, $ Be $ doesn’t give this test.
Beryllium and magnesium do not give any colour to the flame test because they have a small size and very high ionization enthalpies. The energy of the flame is not sufficient to excite the electrons to higher energy levels. Hence, they do not impart any characteristic colour to the flame.
Example: Suppose if an electron absorbs red-colored radiations and gets excited, then the radiations emitted would be of the opposite color i.e. of the violet color.
Therefore, the correct answer is option (C).

Note:
Remember that The elements give flame test due to the excitation of the electrons to the higher energy levels i.e. when electrons present in an atom gains energy, they jump to the higher energy levels and when these electrons return back to their orbits, they emit energy in form of radiations and the color of the radiations emitted is contrary to the color of the radiations which they absorbed during the excitation.