The greatest inaccuracy in Copernicus' model of the solar system ...

[Tazate]

The greatest inaccuracy in Copernicus' model of the solar system was that the planets
 
  a. travel in circular orbits with uniform motion.
  b. traveled on epicycles whose centers followed orbits around the Sun.
  c. traveled in elliptical orbits.
  d. were allowed to travel backwards in their orbits.
  e. the planets orbited the Sun.

Question 2

The proton-proton chain
 
  a. combines two hydrogen nuclei to produce a single helium nucleus and energy.
  b. splits a helium nucleus to produce 4 hydrogen nuclei and energy.
  c. is the mechanism that increases the temperature between the photosphere and corona of the sun.
  d. is the interactions between protons in Earth's atmosphere that produces auroras.
  e. produces energy in the core of the sun in the form of gamma-rays, positrons, and neutrinos.

[bookworm410]

Answer to Question 1

A

Answer to Question 2

E

[Tazate]

Thanks for the timely response, appreciate it

[isabelt_18]

TYSM