Wastewater Story — Science STD 7 — Question

State two ways in which water returns to the Earth’s surface in the water cycle.

A food stall owner was preparing dough for making bhaturas. He added a pinch of yeast and sugar to the dough and left it in a warm place. After few hours, the dough had risen. There was a sour smell too. What would have happened if the dough was kept in the refrigerator, soon after it was prepared?

Explain the process of breathing in insects and fishes.

Why is chlorophyll important for the production of starch in plants?

What is the difference between an incandescent lamp and an LED lamp?

How can you identify vinegar, baking soda solution, and sugar solution using turmeric paper?

Explain the role of the diaphragm in the process of breathing.

The freezer is located at the top of the refrigerator. Explain why?

Explain the construction of a battery.

Explain how in ancient time a day, a month and a year were measured.