书城教材教辅科学读本(英文原版)(套装1-6册)
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第102章 第二册(19)

"See now, Norah," he added, "the jelly has become a thin clear liquid. The starch is dissolved at last.""Oh, I see," said Norah; "the starch will not dissolve in cold water, but it dissolves in boiling water.""Now, look at the other starch in the tumbler of cold water," said Fred.

"Why, the water is quite clear now," said Norah. "Where is the starch?""Look at the bottom of the tumbler," cried Willie. "It has all sunk down there. If we pour off the water, we shall leave all the starch at the bottom. None of it is in the water, because it will not dissolve in cold water."SUMMARY

Starch is not soluble in cold water. Like chalk, it sinks to the bottom, and we can pour the water away. We can dissolve starch in boiling water.

What Starch is