The half-life of Strontium-90 is 28.8 years. how long will it take for 3/4 of a sample of Strontium-90 to decay? (you can include work but u don’t have to)

What element breaks down into yttrium-90?

According to the diagram, what sources contribute to the phosphorus found in soil? according to the diagram, phosphorus found in soil contributes phosphorus to what other sources?

Which property of a rock remains unchanged by mechanical weathering? a. total surface area b. size and shape c. mineral composition d. sharpness