# Physics Flashcards - Atomic and Nuclear Phenomena

 Is the energy of a photon dependent on frequency or on amplitude? The energy of a photon is dependent on frequency. What is the formula for calculating the energy of a photon? E = E = (Planck's constant)(frequency) = hf What is the photoelectric effect? The photoelectric effect is the phenomenon whereby electrons are emitted by a metal that is exposed to light of a sufficiently light frequency. (T/F) Photon energy increases when wavelength increases. False. Photon energy decreases as wavelength increases, as seen from the formula... What is the threshold frequency (photoelectric effect)? The threshold frequency is the minimum frequency of light that will cause the emission of an electron. (T/F) The excess energy of a photon is converted to extra kinetic energy of the emitted electron. True. What is the formula for calculating the kinetic energy of an emitted electron? K = K = hf - W  (W = hfT), where fT is threshold frequency. How many electrons will be emitted when using light with a frequency below the threshold frequency. None (T/F) The electron Volt (eV) is a unit of energy. True. What happens to an electron that absorbs a photon? An electron that absorbs a photon will jump to a higher energy level. What happens when an electron jumps from a higher energy level to a lower energy level (orbit)? An electron that jumps from a higher energy level to a lower energy level will emit a photon whose energy equals the difference in energy between the two levels. What is the minimum energy needed to ionize an electron in a state with energy -10eV? 10eV. Ionization means producing a free electron and  free electrons have energy greater than or equal to zero. What is a nucleon? A nucleon is a proton or a neutron. What does an atom's atomic number represent? Atomic number represents the number of protons in the atom's nucleus. What does an atom's mass number represent? Mass number represents the number of nucleons (protons + neutrons) in the atom's nucleus. What is an isotope? An isotope is a variant of an atom with the same number of protons but with a different number of neutrons. What does an atom's atomic weight represent? Atomic weight represents the weighted average of the masses of the naturally occurring isotopes of an element. What do "Z" and "A" represent in the following isotopic notation? Z = atomic number A = mass number What is mass defect? Mass defect is the difference between the mass of a nucleus and the sum total of its constituents (nucleons). What formula is used for calculating binding energy? Energy = (mass defect)(speed of light)2 = Δmc2 What is the name of the process for combining smaller nuclei into larger nuclei? Fusion is the combining of smaller nuclei to create larger nuclei. What is nuclear fission? Fission is the splitting of atomic nuclei. What happens to an atom's mass (A) and atomic (Z) numbers when an alpha (α) particle is emitted? Adaughter = Aparent - 4 Zdaughter = Zparent - 2 What happens to an atom's mass (A) and atomic (Z) numbers when it undergoes β- decay? Adaughter = AparentZdaughter = Zparent + 1 What happens to an atom's mass (A) and atomic (Z) numbers when it undergoes β+ (positron) decay? Adaughter = AparentZdaughter = Zparent - 1 What happens to an atom's mass (A) and atomic (Z) numbers when it undergoes gamma (λ) decay? Adaughter = AparentZdaughter = Zparent If the half life of an isotope is 2 years, how much of the original isotope will be left after 4 years? 25% will be left after two half-lives. What is the formula for exponential decay? The formula for exponential decay is Authorawc1990 ID212604 Card SetPhysics Flashcards - Atomic and Nuclear Phenomena DescriptionPhysics Flashcards - Atomic and Nuclear Phenomena Kaplan MCAT P64-P71 Updated2013-04-10T07:42:25Z Show Answers