Green light has a wavelength of 5.4 107 m. What is the frequency of this EM-wave in air?
a. 5.55 1014 Hz
b. 6.00 1011 Hz
c. 9.00 108 Hz
d. 3.00 1010 MHz
e. 1.80 1015 Hz
Question 2
An extremely large collection of stars bound together by gravitational attraction and occupying a huge volume of space is called a _______________.
a. planetary nebula
b. solar system
c. universe
d. galaxy