how many helium atoms must undergo fusion at 100 million K in the helium flash?
To determine how many helium atoms must undergo fusion in the helium flash at a temperature of 100 million K, we need to consider the conditions required for fusion and the energy released by each reaction.
During the helium flash, nuclear fusion occurs in the core of a star when helium nuclei (alpha particles) combine to form heavier elements. This process only occurs in stars with a certain mass range, typically between 0.5 and 10 times the mass of the Sun.
In order to initiate fusion, the core temperature must reach about 100 million K. At this temperature, helium nuclei can overcome their mutual electrostatic repulsion and approach each other close enough for the strong nuclear force to bind them together. The reaction that takes place is known as the triple-alpha process.
The triple-alpha process involves the fusion of three helium nuclei (each containing two protons and two neutrons) to form a carbon nucleus (with six protons and six neutrons). It can be represented by the following equation:
4He + 4He + 4He → 12C
In this reaction, three helium nucleus collide and ultimately one carbon nucleus is formed. The mass of three helium nuclei (4 atomic mass units each) is 12 atomic mass units, which is equivalent to the mass of a carbon nucleus.
Therefore, to calculate the number of helium atoms required for fusion in the helium flash, we need to determine the total mass of helium atoms in the core and divide it by the mass of a single helium atom.
Since we know that one helium atom has a mass of approximately 4 atomic mass units, and the mass of the core is determined by the mass of the star, we can divide the mass of the core by 4 to find the number of helium atoms. However, without information about the mass of the star or its core, we cannot provide a specific answer.
Therefore, to determine the precise number of helium atoms required for fusion in the helium flash at a temperature of 100 million K, we would need to know the mass of the star and perform the necessary calculations.