An atom of helium has a radius of and the average orbital speed of the electrons in it is about Calculate the least possible uncertainty in a measurement of the speed of an electron in an atom of helium. Write your answer as a percentage of the average speed, and round it to significant digits.

Which of the following statements about acidic water is true? a. acid has no effect on the h,o molecules. b. the solution contains a larger number of oh ions than h,o ions. c. the solution contains a larger number of h,o ions than qh ions. d. the solution contains an equal number of h,o ions and oh ions. none of the above e.

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?

If a straight-chain hydrocarbon is a gas at room temperature, how many carbon atoms will it have? a. 6 carbon atoms b. 12 carbon atoms c. 24 carbon atoms d. 3 carbon atoms