Q. Our editing department is stumped! Would you say “There are an infinite amount of critical values” or “There is an infinite amount of critical values”?
A. Neither. The word amount is normally used only with singular noncount nouns. You have a number or quantity of Xs, but an amount of X (singular): a large amount of cash, a small amount of pride, a piddling amount of rain, but an infinite number of critical values.