In the p-p chain, shown in the above diagram, what particles must be input in order to produce one 4He nucleus?
A: 8 protons, but 2 of them are returned when the 4He is produced
B: 6 protons, but 2 of them are returned when the 4He is produced
C: 2 photons and 2 positrons
D: 2 protons and 4 neutrons
E: 4 neutrons
In what box does the galaxy in the bottom center belong in this Hubble tuning fork diagram?
In the figure above, how would you calculate the fraction of the mass of the gas in the universe that is in the
form of Helium?
A: take 4x4 for the mass of Helium and divide by 4x4+48x1 for the total mass
B: take 4x1 for the mass of Helium and divide by 48x1 for mass of Hydrogen
C: take 4 for the mass of Helium an divide by 48 for the mass of Hydrogen
D: take 48x1 for the mass of Hydrogen and divide by 4x4+48x1 for total mass
E: take 48x4 for the mass of Hydrogen and divide by 4x1 + 48x4 for total mass