1. The Earth and the Sun
-Hydrogen (about 70%) is the Sun’s main fuel source
-Helium (about 25%) and energy are the main products of fusion from the Sun
-there are other elements too, but these are not from fusion in the Sun itself but, according to scientists, from traces of other stars that came before the Sun

2. The Earth and the Sun
-The sun is predicted to last for 10 billion years based on its mass and the life cycle of other stars
-this is based on radioactive dating of other stars of similar origin in time and by calculating how much “energy” is left in the Sun

3. Energy Content (MJ/kg)
The Earth and the Sun
-Based on the amount of energy coming from the Sun, the only process that could allow for this is fusion
-chemical energy is not sufficient to produce the same amount of energy for such long periods of time
Fuel Type
Energy Content (MJ/kg)
Wood 15
Sugar 17
Coal
23-29
Gasoline 45
Methane 55
Nuclear Fission (U)
90,000
Nuclear Fusion (H)
300,000

4. Fission vs. Fusion Compare and contrast fission and fusion. Fission