question_answer 6)

Will the tiny air bubbles seen before the water actually boils also appear if we do this activity by reheating boiled water kept in an air tight bottle?  

Answer:

Bubbles are seen because on heating the water, the air which is already present in it, in dissolved form tends to escape out. Water after boiling if kept in air tight container and then rebelled, there will no bubbles due to the absence of air.