Stars and elements Crossword

One of the first elements created in the Big Bang
The last stage in an average stars life
The first stage in a stars life
The third stage in an average stars life
When lighter elements fuse to create heavier elements with the release of energy
The process that creates new protons and neutrons
When a massive star starts to reach the end of its life span and explodes leaving behind lots of energy
One of the first elements created in the Big Bang
One of the last stages in a massive stars life
One of the last stages in a massive stars life
The fourth stage in an average size stars life
The stable stage in a stars life
An increase or decrease in the frequency of sound as the object passes by
All existing matter and space considered as a whole; the cosmos
A cluster of stars
A force that attracts a body to the center of the earth
The theory that marks the origin of the universe