A painter and his helper are standing on a scaffold. The painter weighs 400 newtons. The helper weighs 300 newtons. The tension in a rope A is 925 newtons. The tension in rope B is 825 newtons. What Is the weight of the board?

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

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.

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?