200g*1 mole/ 18g=11.1 moles There are 11.1 moles of water.
Answer:
C. Fill two identical pots with equal volumes of salt water and tap water and use a stopwatch to determine the time it takes each pot to boil.
Explanation:
<u>A) is incorrect</u> because Peter should have the same testing environment for both of his experiments.
He should choose the same method of boiling the salt water and tap water because the stovetop and the microwave could also affect the results and make them unreliable.
<u>B) is incorrect</u> because Peter should not estimate the time it takes the salt water and tap water to boil.
Peter should measure and record the amount of time that it takes these substances to boil in order to have an accurate, valid experimental thesis.
<u>C) is correct</u> because Peter uses the same volume of salt water and tap water, fills them into two identical pots, and uses a stopwatch to determine the amount of time it takes each pot to boil.
The stopwatch makes the experiment more valid and accurate compared to the previous methods, and the identical pots and amounts of water help this experiment become even more precise.
<u>D) is incorrect</u> because the variables in the experiment are not controlled amounts and will therefore produce an inaccurate and invalid experiment.
F - False.
The nucleus of an atom is positively charge.
Answer:

Upward
Explanation:
We are given that
Mass of scarp paper,
1mg=
Distance,d =8 mm=
Magnitude of electric force =
Where 
Substitute the values


Gravitational force act in downward direction.
The electric force acts in opposite direction and magnitude of electric force is equal to gravitational force.
Hence, the direction of electric force is upward.
The answer is 8.
Hope I helped.