Chlorine is micronutrients, too much chlorine may lead to toxicity in plants, it can result in to burned appearance in leaves.
The nutrients which are less Essential to plants for there growth. For example Boron, chlorine, mangnese, molybdenum, iron, zinc.
Chlorine is also on of micronutrients , it not that much essential and if there is too much chlorine it can lead to brown or dead tissue on the tips ,margins between the veins of leaves.
As she has put chlorine in plants without the particular amount needed the plant ,so the plants lead to toxicity. And the fifth plant do not contain any chlorine it is alive.
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