The Big Bang Theory

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Across
  1. 6. More stable particles called protons and ______________ started to form when the Universe was one second old.
  2. 7. Time, space and, ___________ all began with the Big Bang
  3. 8. After 300,000 years, the universe filled with ___________ of hydrogen and helium gas
Down
  1. 1. the Universe suddenly _________________ when it was born
  2. 2. As the Universe expanded and cooled, energy changed into ______________of matter and antimatter
  3. 3. before the Big Bang, the Universe was hotter and ____________ than anything we can imagine
  4. 4. The Universe started in a bubble thousands of times smaller than a _________________
  5. 5. In a fraction of a second, the Universe grew from smaller than a single _________ to bigger than a galaxy