Jack tries to place magnets on the door of his refrigerator. he observes that the magnets don’t stick. he guesses that the door of the refrigerator is made of a nonmagnetic substance. what stage of scientific investigation does his guess represent?

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

answer: glucoamylase presented optimum activity at temperature of 55â°c, and, in the glycosidic bonds from the non-reducing ends of starch, resulting in the production of glucose. source and type of fermentation can affect the enzyme's properties

credit to kalahira