PLEASE HELP! A sample of radioactive waste will have reached an acceptable activity level at 0.5 curies . If the half - life of the sample is 5 years and the sample can be disposed of after a minimum of 20 years , what must the original activity level of the sample be ?

Which property is used to identify the origin of an igneous rock? color density hardness crystal size

In which specialized organ of the plant would these cells most likely be found

3points hurry! what is the relationship between biotechnology, sharkskin, and disease resistance? bioengineers have developed an artificial sharkskin that does not allow resistant bacteria to grow on it. disease-causing microbes have been genetically modified to keep them from infecting the skins of sharks. scientists have created a device that can be attached to the skins of sharks that dramatically increases their abilities to resist disease. sharkskin produces many chemicals that can be collected and used to create antibiotics.