Hydrogen atoms can emit four lines with visible colors from red ...

[anjilletteb]

Hydrogen atoms can emit four lines with visible colors from red to violet. These four visible lines emitted by hydrogen atoms are produced by electrons
 
  A) that start in the n = 2 level.
  B) that end up in the n = 2 level.
  C) that end up in the n = 3 level.
  D) that end up in the ground state.
  E) that start in the ground state.

Question 2

A concave mirror has a focal length of 20 cm. A paraxial beam of light coming from a distant object forms its image at the focal point.
 
  If a small plane mirror is placed at the center of curvature with its reflecting side facing the focal point, where is the final image? A) 3 cm in front of the mirror
  B) 40 cm in front of the mirror
  C) 50 cm in front of the mirror
  D) 60 cm in front of the mirror
  E) 70 cm in front of the mirror

[gstein359]

Answer to Question 1

B

Answer to Question 2

D

[anjilletteb]

Gracias!

[jojobee318]

Excellent