17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
Answer:
They include frequency, period,speed,amplitude and phase
It’s the nerves but I’m not 100% sure if I’m correct
Answer:
2 C Atoms
Explanation:
When you have coefficient of 2 next to a compound element, it indicates there are 2 of each compound element. In the compound element, there is one C Atom, and 2×1 is 2.