Answer:
C. BF3
Explanation:
The boron in BF3 is electron poor and has an empty orbital, so it can accept a pair of electrons, making it a Lewis acid.
Since f=ma assuming you knew the mass of the marble and the total amount of force acting on it than you would divide the amount of force by the mass.
Frequency = speed of light/ wavelength of photon. wavelength = speed of light/frequency = 3 x 10^8 / 2.43 x 10^8= 1.23m