In India on the occasion of marriages, the fireworks give off a green flame. Which one of the following radicals may be present A. Na B. K C. Ba D. Ca
Hint: Fireworks in Indian marriages are a very common practice. These fireworks give several colours like green, red, orange, etc. This is because these fireworks contain metal salts.
Complete Step by Step Solution: The heating of a salt furnishes a quantity of energy to the salt. This energy is consumed by the substance so the flame is detected with a colour.
When a specific quantity of energy is furnished to any combination, the energy of the atoms inside the substance heightens as the substance absorbs this provided energy. If a metal salt undergoes heating then the electrons present inside its atoms absorb this energy, are excited and then are lifted to a higher energy level above their ground state.
When these electrons regain their original position i.e., ground state, they radiate energy. This energy comes out as visible light with distinctive colours. So, the flame of an element possesses a distinct colour. This is indicated largely by alkali metals and alkali earth metals. These metals have less ionisation energy so, it is effortless to eliminate an electron from the outer shell of these metals. Out of the provided options, the flame of salts of Barium is green. So, option C is correct.
Note: Metal salts generally employed in fireworks are strontium carbonate for red fireworks, calcium chloride for orange fireworks, sodium nitrate for yellow fireworks, barium chloride for green fireworks etc. So, the metal salt that has a green flame is barium chloride.