How can radioactive decay tell scientists how old a substance is?

Imagine that you have produced several versions of lactase, each of which differs from normal lactase by a single amino acid. describe a test that could indirectly determine which of the versions significantly alters the three-dimensional shape of the lactase protein.

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?

‘which reaction would most likely require the use of an inert electrode?