Nuclear Physics Flashcards
Only the speed of light in a vacuum is _. Length and time are not because of this.
Constant
What is the mass and energy of a photon?
It is massless and E=hf
what is the strong nuclear force equal to?
Mass defect
What is Headlight Effect?
Beam becomes focused. Same amount of light concentrated in a smaller area. Torch appears brighter!
What is the work function?
“The amount to ionize the electron. The work function ( ϕ ) is the energy needed by an electron in the ground state to reach the edge of the atom. In the atom below you need to add 10 eV to move from the ground state (−10 eV) to the edge of the atom ( 0 eV ).
ϕ = +10 eV”
How is a photocell a battery?
Light strikes the atoms in the photo cell ejecting them with Kmax, and causing them to travel to another plate which then becomes negative. The atoms that gave up electrons now become positive. Connecting the plates with a wire allows the negative electrons to travel back to the positive plates so the process can begin again and again.
What is the stopping voltage?
No current because the electrons keep getting pushed back.
What is the evidence for wave effect vs. partical effect?
Difraction and interference are wave effects and photoelectric effect is partical effect.
What are some factors of graphing the photoelectric effect?
The graph is only graphed positive. Photoelectric effect involves electrons that have escaped the atoms. Energy values are negative for electrons inside the atom (energy level problems. This is why the x-intercept is known as the threshold frequency. Below this cut off there is no photoelectric effect.
What us the Compton Effect?
Arthur Compton discovered that x-ray photons when collided with electrons in a graphite crystal displayed particle properties of momentum equal to h / λ. Similar to two pool balls hitting each other, and when it is put through a crystal, he found that any particle can have a wavelength associated with it. Anything that has momentum has a wavelength associated with it.
What is evidence for particle theory of light?
The Compton Effect
What is the de Broglie’s Hypothesis?
Each electron orbit in an atom is a standing wave, specifically a circular standing wave that closes upon itself.
What are isotopes?
Nuclei that contain the same atomic number but a different mass number.
What is an mass defect?
The total mass of a stable nucleus is always less than the sum of the masses of its constituent protons and neutrons. The mass of the parts of a neuclus is bigger than them as a whole. Mass defect is mass parts-mass whole. In energy this is the binding energy.
What is fission and fusion?
On a BE/A vs #A with iron-56 at top because thats when starts stop fusing (coming together) and then after is fission and then they start fisioning and iron is stable.
