Away from you. This is known as the Doppler affect. It basically states that if an object is moving away from you the streching of the wave causes a red shift and if the object is moving towards you the compression of the waves causes a blue shift.
<u>Answer:</u> The number of moles of ammonium nitrate is 0.004 moles.
<u>Explanation:</u>
To calculate the number of moles for given molarity, we use the equation:

We are given:
Molarity of
solution = 0.125 M
Volume of solution = 32.5 mL
Putting values in above equation, we get:

Hence, the number of moles of ammonium nitrate is 0.004 moles.
To predict the solubility of the compounds you should base on solubility tables.
I used one from wikipedia. If you google "solubility table" you will find this table as first option.
There I found that nickel, potassium and sodium chlorides are very soluble with solubilities of two digits. While lead clhoride has a solubility close to 1 g per 100 g of water. Then lead is the ion that will precipitate with certainty.
Answer B: The water is touching the bottom of the pan, but not the heat source.