What are the blank ones?

Calculate the frequency of a wave in a spring toy. the wave has a speed of 1.1 meters per second and a wavelength of 0.1 meters. *

2-bromo-2-methylbutane undergoes an e1 elimination reaction in the presence of ethanol. in the next reaction only one of the possible products is represented. although the product shown is not the major product of the reaction, notice that there is more than one way it can be produced. complete the mechanism and draw the missing substances.

How many atoms are in 2 moles of phosphorus