Iobium-91 has a half-life of 680 years. after 2,040 years, how much niobium-91 will remain from a 300.0-g sample?

Effect of rotenone and antimycin a on electron transfer rotenone, a toxic natural product from plants, strongly inhibits nadh dehydrogenase of insect and fish mitochondria. antimycin a, a toxic antibiotic, strongly inhibits the oxidation of ubiquinol. (a) explain why rotenone ingestion is lethal to some insect and fish species. (b) explain why antimycin a is a poison. (c) given that rotenone and antimycin a are equally effective in blocking their respective sites in the electron-transfer chain, which would be a more potent poison? explain.

12. calculate the hydroxide ion concentration of a solution with ph = 3.25. show all calculations leading to an answer

What is the work done by the electric force to move a 1 c charge from a to b?