The model after John Dalton's was J.J Thompson's plum podding model in 1897, which described electrons as dots or raisins(if you will) in a circle shaped pudding that was entirely positive using a Cathode Ray Tube(shot cathode rays between magnets). The model after that is the Niels Bohr model in 1913, which depicts atoms like positively charged center called the nucleus with negatively charged particles called electrons in a shell or cloud.
<span>c = speed of light = 3.00 x 10^5 km/s = 3.00 x 10^8 m/s
λ = wavelength of the microwave radiation = 3.50 cm = 0.035 m
f = frequency (in Hertz) = to be determined
f = c/λ = 3.00 x 10^8 m/s / 0.035 m
f = 8.57 x 10^9 Hz Frequency</span>
The answer to your question is A.
P2O5 = Phosphorus pentoxide
CuO = Copper (II) oxide
NH4CI = Ammonium Chloride
Mn(OH)2 = Pyrochroite
H2O2 = Hydrogen peroxide
P4S9 = Tetraphosphorus nonasulfide
CIO2 = Chlorine dioxide
NaF = Sodium fluoride
FeSO3 = Iron (II) Sulfite
Fe(NO3)3 = Iron (III) Nitrate
Cr(NO2)3 = Chromium (III) Nitrite
NaHCO3 = Sodium Hydrogen Carbonate
H2PO4 = Dihydrogen Phosphate Ion
NaCN = Sodium Cyanide
IF7 = Iodine Heptafluoride
PCI3 = Phosphorus Trichloride
