Answer:
the formula is efficiency = output / input × 100%
In a closed system, energy in form of heat (work) can be exchanged but not matter.
The answer to your question is C.
Hope it helped!
Answer:

Explanation:
The total charge is distributed over the two objects:

The plate and the rod must have
. So the charge transferred from the plate to the rod is:

Number of electrons:

Answer:
a = 2d / t²
Explanation:
d = ½ at²
Multiply both sides by 2:
2d = at²
Divide both sides by t²:
a = 2d / t²
Which element is less reactive, an element whose atoms have seven valence electrons or an element whose atoms have eight valence electrons? Why?<span>an element with 8 valence electrons because it doesn't require any additional electrons to become stable</span>