D. is the answer
hope i could help
O valence electron number is the answer
I will take a stab at it, but there are not equations, did you forget them?
Question 17:
False; cutting hair would change what it looks like but, braiding it keeps it the same substance it is.
Question 18 :
My best guess would either be A or D. I would lean more towards D because if there are different mixtures then it depends on what you are mixing.
Hope it helps in some way. <3
