The element lead (pb) consists of four naturally occurring isotopes with atomic masses 203.97302,205.97444,206.97587, n 207.97663 amu. the relative abundances of these four isotopes are 1.4,24.1,22.1, and 52.4 %, respectively. write the most common isotope of lead in two ways

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.