Science 10 with CSS teacher

The Big Bang theory was developed in the early 1900s. It states that about 15 billion years ago an explosion caused the expansion of matter and radiation into space. The explosion was the beginning of space and time as we know it. Seconds after the explosion, energy was converted into particles and anti-particles (i.e. electrons and positrons). Within minutes, traces of hydrogen and helium nuclei were created. Millions of years later, stars and galaxies began to form. The chemical reactions in stars created all the other elements found in the Universe today. 

Watch the video below to learn more about the Big Bang Theory to explain the formation of the Universe.