In which of these situations would light slow down?

a. from plastic to air
b. from ice to water
c. from a vacuum to air
d. from glass to air

Option (C) from a vacuum to air

Explanation:

Speed of light in any media depends on the refractive index(n) of the medium in which light is travelling.The medium having least refractive index have the fastest speed of the light.As the refractive index of the vacuum is less(1.0000) than that of the air(1.0003), so the speed of light will slows down while moving from vacuum to air.The refractive index 'n' is the ratio between speed of light in vacuum(c) to the speed at which the light is travelling i.e v,  (n = c / v).

by cartels in other countries, shipped by air, mail, or land. i cant really see your answer choices : /

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.