Jenna took an open bowl of leftover mashed potatoes from the refrigerator. She determined that chemical changes occurred since the potatoes were first placed there. Which observations most likely led to Jenna's conclusion

a change of odor

Explanation:

When a chemical change occurs, a new substance is formed. Because of this, there might be indicators or changes that occur to show you what happened. One of these is a change of odor. If there is a change of odor in a substance, that means that a chemical change has occurred.

- I took the quiz and got 100%

Hope this helps!

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally