Twelve hours of daytime and twelve hours of nighttime occur at ...

[bclement10]

Twelve hours of daytime and twelve hours of nighttime occur at every location on Earth whenever the Sun reaches the
 a. north or south celestial pole.
  b. celestial prime meridian.
  c. vernal or autumnal equinox.
  d. ecliptic.

Question 2

Niels Bohr focused his attention on the element hydrogen because it
 a. could be obtained in extremely high purity.
  b. was so abundant.
  c. had the simplest atom.
  d. was inexpensive.

[lkanara2]

Answer to Question 1

c

Answer to Question 2

c

[bclement10]

Both answers were spot on, thank you once again

[lkanara2]

Great! Please up vote