Qual é a cor do arco-iris que possui maior intensidade? E a cor que possui a menor intensidade?

Achemist has dissolved a certain substance in water. the chemist knows that more of the substance could be dissolved into the water before it stops dissolving. therefore

If 15 drops of ethanol from a medical dropper weight 0.60g, how many drops does it takes from a dropper to dispense 1.0ml of ethanol? the density of ethanol is 0.80g/ml

Which of the four hypothetical substances you investigated would be most harmful to living organisms? 50 points!