Category Archives: WHAT?
16. WHAT MAKES A WATERFALL?
When a stream or river plunges over a wall of rock called a cliff or a recipice, we have a waterfall. If the waterfall is of great size, it is called a cataract. Where the rock wall is steeply slanted rather than vertical, the rushing water is called a cascade.
Sometimes in a cascade, the water descends in a whole series of steep slopes.
15. WHAT IS YEAST?
If a weak sugar solution is exposed to the air, in several days a light, frothy scum appears on the surface and the liquid begins to smell of alcohol. This change takes place because tiny plant cells called yeast have settled from the air into the liquid. They have found conditions favorable to their growth.
14. WHAT IS A WATERSPOUT?
A waterspout and a tornado are very similar. In fact, you might call a waterspout a tornado at sea. So let’s first see what a tornado is. A tornado is really a circular storm. It begins as a black, funnel- shaped cloud in a larger thunderstorm area. The funnel of the cloud is caused by the condensation of moisture through cooling of the air as it expands and is lifted upward.
