Radio waves are reflected by which of the following ion layers?
a. C
b. D
c. F
d. A
c
You might also like to view...
The correct value for the speed of light in air is
A. 1.86 × 105 feet/s. B. 3 × 105 km/h. C. 1.86 × 105 miles/h. D. 3 × 108 m/s. E. 3.0 × 105 m/s.
The sunspot cycle has a period of
a. 19 years. b. 11 years. c. 38 years. d. 24 years.
Which has the events in the right order, from early to late?
A.) Star formation, quark soup, protons form, atoms form, nucleosynthesis. B.) Quark soup, protons form, nucleosynthesis, atoms form, star formation. C.) Nucleosynthesis, star formation, protons form, atoms form, quark soup. D.) Quark soup, atoms form, star formation, protons form, nucleosynthesis. E.) Atoms form, star formation, protons form, quark soup, nucleosynthesis.
The present motions of the planets were inherited from the rotation of the solar nebula
Indicate whether the statement is true or false