Each photon in a beam of light has an energy of 4.20 eV. What is ...

[HCHenry]

Each photon in a beam of light has an energy of 4.20 eV. What is the wavelength of this light? (c = 3.00  108 m/s, h = 6.626  10-34 J  s, 1 eV = 1.60  10-19 J)
 
  A) 321 nm
  B) 103 nm
  C) 296 nm
  D) 412 nm
  E) 420 nm

Question 2

The earth's orbit has a mean radius of 1.5  108 km. Over a six-month period, the apparent position of a particular star varies by 0.00014 due to parallax.
 
  How many kilometers is this star from Earth?
  A) 1.2  1017 km B) 1.2  1014 km C) 1.2  1020 km D) 1.2  1011 km

[tennis14576]

Answer to Question 1

C

Answer to Question 2

B