17. Heat
18. Evaporation
Answer:
0.8 - 1.25
Explanation:
f = n ÷ t
period = 1 ÷ f
f = 20/25 = 0.8 Hz
period = 1/0.8 = 1.25 s
Answer is in the photo. I can't attach it here, but I uploaded it to a file hosting. link below! Good Luck!
tinyurl.com/wpazsebu
dont know sorry
