Juliet started working with a radioactive substance. In 1997, she started with 200 g. When she measured again in 2002, she had 100 g left. In 2007, she had 50 g. Which substance is she most likely measuring?

rubidium-91
iodine-131
cobalt-60
carbon-14

Ineed this answered asap the north korean communist government a. controls crop production and distribution. b. is not involved in crop production and distribution. c. exports its huge rice surplus to other countries. d. allows farmers to choose which crops to grow but controls where the crops are sold. which statement below is true? a. east asian nations are members of nafta. c. industry and production is not an important aspect of east asian economics. b. east asian nations are economically independent. d. the economies of most east asian countries are mixed or market systems. what is the main idea of this passage? a. the city of hiroshima can never fully recover from the atomic bombing of 1945. b. hiroshima is more modernized than any other city in japan. c. after being bombed, hiroshima was rebuilt and became a thriving urban port. d. the city of hiroshima has an extensive park system dedicated to peace.