Question bank/JEE Main/Chemistry
JEE MainChemistryEasyInorganic Chemistry
Select the correct statement with respect to alkali metals.
Show answer and solution
(1) Down the group due to increase in size the strength of
metallic bond decreases and so, melting point decreases.
(2) Atomic volume of K is larger as compared to Na. Increase in atomic
mass does not over come the effect of increase atomic volume in case of
potassium.
(3) They have low ionisation energies because of their larger atomic
size. The heat from the flame excites the outer most orbital electron
to a higher energy level. When the excited electrons come back to the
ground state, there is emission of radiation in the visible region.
Hence, salts of Li to Cs impart characteristic colour to an oxidising
flame (of Bunsen burner).
metallic bond decreases and so, melting point decreases.
(2) Atomic volume of K is larger as compared to Na. Increase in atomic
mass does not over come the effect of increase atomic volume in case of
potassium.
(3) They have low ionisation energies because of their larger atomic
size. The heat from the flame excites the outer most orbital electron
to a higher energy level. When the excited electrons come back to the
ground state, there is emission of radiation in the visible region.
Hence, salts of Li to Cs impart characteristic colour to an oxidising
flame (of Bunsen burner).
Source: Grass-G / CH-28 Chemistry Paper FST 16 Jan.docx
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