The focal length, like you said it's the distance between the FOCAL point and the mirror.
Hope this helps.... :)
<u>Answer:</u> The amount of water required to prepare given amount of salt is 398.4 mL
<u>Explanation:</u>
To calculate the volume of solution, we use the equation used to calculate the molarity of solution:

We are given:
Molarity of solution = 0.16 M
Given mass of manganese (II) nitrate tetrahydrate = 16 g
Molar mass of manganese (II) nitrate tetrahydrate = 251 g/mol
Putting values in above equation, we get:

Volume of water = Volume of solution = 398.4 mL
Hence, the amount of water required to prepare given amount of salt is 398.4 mL
A. Gamma radiation because it reaches further than beta and alpha rays
Answer:
802.69 g
Explanation:
The molar mass of Barium nitrite is 229.34 g/mol, so 3.5 moles of it will have a mass of ...
3.5 mol × 229.34 g/mol = 802.69 g