The first model of the atom was developed by JJ Thomson in 1904, who thought that atoms were composed purely of negatively charged electrons.
This theory was then disproved by Ernest Rutherford and the gold foil experiment in 1911, where Rutherford shot alpha particles at gold foil, and noticed that some went through and some bounced back, implying the existence of a positive nucleus.
In 1926, the Austrian physicist Erwin Schrödinger created a quantum mechanical model of the atom by combining the equations for the behavior of waves with the de Broglie equation to generate a mathematical model for the distribution of electrons in an atom.
The CNO cycle, the abbreviation for the carbon-nitrogen-oxygen cycle, is a catalytic cycle by which the stars produce helium from elemental hydrogen, via a series of nuclear fusion reactions.
This cycle involves the fusion of four protons with carbon (), nitrogen isotope (), and oxygen isotope (), to give an alpha particle and two electron neutrinos and positrons.
The reaction involves the regeneration of carbon () nucleus in the last step.