Beyond the formation of iron, nuclear energy can be produced only ...

[Wadzanai]

Beyond the formation of iron, nuclear energy can be produced only by
 
  A) fusion of still heavier elements.
  B) ionization of the radioactive nuclei.
  C) fission of heavy nuclei back toward lighter ones.
  D) gravity.
  E) the dark force.

Question 2

When did humans learn that the Earth is not the center of the universe?
 
  A) within the past 500 years
  B) about 2,500 years ago
  C) about 1,000 years ago
  D) We haven't; there is still considerable scientific debate about whether Earth is the center of the universe.

[meltdown117]

Answer to Question 1

C

Answer to Question 2

A

[Wadzanai]

TYSM

[ricroger]

Gracias!