Why is Saturn almost as big as Jupiter, despite its smaller mass? ...

[mpobi80]

Why is Saturn almost as big as Jupiter, despite its smaller mass?
 
  A) Jupiter's greater mass compresses it more, thus increasing its density.
  B) Saturn's rings make the planet look bigger.
  C) Saturn is further from the Sun, thus cooler, and therefore less compact.
  D) Saturn has a larger proportion of hydrogen and helium than Jupiter, and is therefore less dense.
  E) Jupiter's strong magnetic field constrains its size.

Question 2

Which of these is constant for ALL types of electromagnetic radiation in a vacuum?
 
  A) amplitude
  B) wavelength
  C) frequency
  D) velocity
  E) photon energy

[cpetit11]

Answer to Question 1

A

Answer to Question 2

D