Copper is made of two isotopes. copper-63 is 69.17% abundant and it has a mass of 62.9296 amu. copper-65 is 30.83% abundant and it has a mass of 64.9278 amu. what is the weighted average mass of these two isotopes? show your work.

How many molecules of sucrose c12h22o11 are there in 454 grams of sucrose

Select each correct answer. more than one answer may be correct. which of the following is a characteristic of unicellular organisms? they can possess tissues and organs. all of their functions are performed by a single cell. they are usually microscopic. each of their cells is specialized to perform a specific function.

Which of the following are sources of revenue for media companies? a. direct sales to producers b. advertising and subscriptions c. online purchase d. capital investments