NASA has released some interesting material on the composition of the Universe - as it is today and as it was 13.7 billion years ago, 1 second after the Big Bang.
Dark Matter, which forms 23% of the Universe, is different from atoms and does not emit or absorb light. It has only been detected indirectly by its gravity.
The bulk of the universe, 72%, is composed of "Dark Energy", that acts as a sort of an anti-gravity. This energy, distinct from dark matter, is responsible for the present-day acceleration of the universal expansion.
Atoms, the building blocks we are made of, comprise of just 4.6% of the Universe.
It's amazing that atoms are so scarce in the Universe and even more amazing how irreverently we treat our Earth and fellow-beings.