A plane electromagnetic wave with wavelength 3.0 m, travels in free space in the+xdirection with its electric field vector~E, of amplitude 300 V/m, directed along they-axis.(a) What is the frequencyfof the wave?

    f =1 10⁸ Hz

Explanation:

The speed of an electromagnetic wave is given by

          c = Lam f

In our case, the wavelength is 3.0 m, so we can clear the frequency

         f = c / Lam

         f = 3 108/3.

         f =1 10⁸ Hz

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂