Read the given expression.
X = number of protons - number of core electrons
Which of the following explains the identity of X and its trends across a period?
X is the effective nuclear charge, and it remains constant across a period.
X is the screening constant, and it remains constant across
period.
X is the effective nuclear charge, and it increases across a period.
X is the screening constant, and it increases across a period.

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.

Which of the following is most likely true about water in chemical systems? a) water dissolves nonpolar ionic compounds. b) water dissociates ionic compounds. c) water dissociates covalent molecules. d) water dissolves nonpolar covalent substances.

When water dissolves sugar, which process is not involved? o dissociation o hydration o surface area of the solute increases sa