240g of Cobalt-60 is allowed to decay for 21 years, how much Cobalt-60 is left? (The half life of Co-60 is 5.26 years.) Please, enter your answer as a whole number with no units.

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

What is the molar mass of ca(cio4)2