Q&A Hero

Q: The symbol indicating the atomic number of a nucleus is A.

Q: Two isotopes have the same mass number.

Q: The atomic number equals the number of protons in a nucleus.

Q: Lithium, Li-7, contains three protons and four neutrons and has a mass of 7.01600 u. What is the mass defect for this nucleus in atomic mass units?

Q: A Geiger counter registers a count rate of 8,000 counts per minute from a sample of a radioisotope. The count rate 24 minutes later is 1,000 counts per minute. What is the half-life of the radioisotope?

Q: A nucleus of sulfur-35 undergoes beta decay. Write the reaction equation and determine the identity of the daughter nucleus.

Q: A nucleus of radium-223 undergoes alpha decay. (a) Write the reaction equation and (b) determine the identity of the daughter nucleus.

Q: Two areas in which fusion is the source of energy are __________ and __________.

Q: Match each item with the correct statement below.a. alpha particle h. hydrogen bombb. atomic bomb i. neutron activation analysisc. atomic mass number j. neutron numberd. atomic number k. nuclear fissione. beta particle l. nuclear fusionf. binding energy m. tokamakg. half-life1/ exploits nuclear fusion2/ the number of protons in a nucleus3/ time interval during which a nucleus has a 50% probability of decaying4/ the total number of nucleons in a nucleus5/ the splitting of a large nucleus into two smaller nuclei6/ the same as a helium-4 nucleus7/ indicates how tightly bound together a nucleus is8/ involves inducing radioactivity artificially9/ one design for a controlled fusion reactor10/ this particle is simply an electron ejected from a nucleus

Q: An important factor in producing and controlling a fission chain reaction is the fact that _________ neutrons are much better a causing fission in uranium-235.

Q: In a smoke detector, current flows between the plates because the radiation ___________ the air.

Q: Isotopes of a given element have the same number of _____________ in the nucleus.

Q: The mass of an atom of carbon-12 (Z = 6) is less than the mass of 6 protons and 6 neutrons because of __________.

Q: When uranium-238 (Z = 92) is bombarded with a neutron, it can change into __________.

Q: The determination of the composition of a material by bombarding it with neutrons and monitoring the emitted radiation is __________.

Q: In a nuclear reactor, _________________ are used to limit the number of neutrons passing from one fuel rod to another.

Q: Two things that exploit fission are __________ and __________.

Q: The combining of two nuclei to form a larger nucleus with the release of energy is __________.

Q: The splitting of a large nucleus into two smaller nuclei upon absorbing a neutron is __________.

Q: How tightly the nucleons in a nucleus are bound together is indicated by the nucleus's __________.

Q: If a piece of wood is suspected to be several thousand years old, its true age can likely be determined through use of the isotope _________.

Q: Stars are powered by ________.

Q: The Voyager space probes used electricity provided by __________.

Q: A Geiger counter registers a count rate of 8,000 counts per minute from a sample of a radioisotope. The count rate 24 minutes later is 1,000 counts per minute. The half life of the radioisotope is __________.

Q: The half life of uranium-232 is 70 years. The time for 3/4 of a sample of uranium-232 to decay is __________.

Q: The time interval during which a nucleus has a 50% probability of decaying is its _________.

Q: When a nucleus in an excited state decays to the ground state, a(n) __________ particle is emitted.

Q: When a neutron decays to a proton, a(n) __________ particle is emitted.

Q: When sulfur-35 (Z = 16) decays to chlorine-35 (Z = 17), a(n) __________ is emitted.

Q: When radium-223 (Z = 88) decays to radon-119 (Z = 86), the other particle emitted is a(n) __________.

Q: Two particles that will be deflected by a magnetic field are __________ and __________.

Q: Of the three types of nuclear decay, only __________ does not affect the atomic number of the nucleus.

Q: Nuclear radiation can be detected by using a __________.

Q: A hydrogen atom emits a photon as it makes a transition from then = 4 state to the n= 3 state. The energies of these two states are "0.9 eV and "1.5 eV, respectively.(a) What is the energy of the photon?(b) What is its frequency?

Q: What is the de Broglie wavelength of an electron traveling 100 m/s?

Q: A photon emitted by an excited atom has an energy of 5 eV. What is its frequency?

Q: Find the energy of a photon whose frequency is 5 x 1012Hz.

Q: Four different uses of lasers are __________, __________, __________, and __________,

Q: Match each item with the correct statement below.a. angular momentum h. photoelectric effectb. de Broglie wavelength i. photonc. emission spectrum j. photon absorptiond. energy k. photon emissione. ground state l. uncertainty principlef. hologram m. wave functiong. laser1/ a quantum of electromagnetic radiation2/ light causing electrons to be released from the surface of a metal3/ one way for an excited atom to lose energy4/ in the Bohr model of the atom this is quantized5/ tells us that particles can"t be precisely localized6/ the lowest energy level in an atom7/ causes an electron to make a transition to a higher energy level8/ light amplification by stimulated emission of radiation9/ a three dimensional image made using a laser10/ oscillating atoms in a blackbody have this quantized11/ the aurora borealisis an example of this

Q: Ionization is a process whereby an atom acquires enough energy so that one or more of its electrons __________ from the nucleus.

Q: An electron absorbing an ultraviolet photon will be ejected with a _________ energy than an electron absorbing a violet photon.

Q: The energy of a photon is _________ proportional to its frequency and __________proportional to its wavelength.

Q: A hot luminous solid emits a ______________ spectrum, while a hot luminous gas produces a ______ spectrum.

Q: An atom is said to have been ________ when it absorbs a photon with sufficient energy to free an electron.

Q: In the Bohr model of the atom, a photon may be _________ when an electron jumps from a large, high energy orbit to a smaller, low energy orbit.

Q: The smallest energy of an absorbed photon that will raise a hydrogen atom from its ground state to its first excited state is __________.

Q: The ionization energy of hydrogen is __________.

Q: The energy of the most energetically possible photon emitted is __________.

Q: NARRBEGIN: Energy level hydrogenThe energy level diagram for hydrogenNARRENDThe energy of a photon emitted in a transition from then = 3 state to then = 2 state is __________.

Q: In a laser the emitted light is __________.

Q: Two devices that make use of the wavelike nature of electrons are the ______________ and the __________.

Q: __________ in an x ray spectrum of an atom occurs because of rapid deceleration of the bombarding electrons.

Q: __________ in an x ray spectrum of an atom occur because electrons in the atom make transitions to lower energy levels after being bombarded with high energy electrons.

Q: When the frequency of the light is increased in a photoelectric effect experiment, the energy of the emitted electrons __________.

Q: When the intensity of light is increased in a photoelectric effect experiment, the energy of the emitted electrons __________.

Q: The person who developed the exclusion principle was __________.

Q: The person who developed the concept of a wave function was __________.

Q: The principal founders of the mathematical model of quantum mechanics were __________ and __________.

Q: The person who expounded the uncertainty principle was __________.

Q: The person who first explained the discrete hydrogen atom spectrum was __________.

Q: The person who first explained the photoelectric effect was __________.

Q: When something is restricted to having only certain numerical values, it is said to be ________________.

Q: The person who first explained the blackbody spectrum was __________.

Q: The peak of the radiation curve of a blackbody moves toward larger wavelength as its temperature __________.

Q: The peak of the radiation curve of a blackbody moves upward toward higher intensity as its temperature __________.

Q: In a blackbody, the __________ of the oscillating atoms is quantized.

Q: A __________ is a three dimensional image made using a laser.

Q: In an energy level transition from the n= 2 state to the n =1 state for a hydrogen atom a photon will be ___________.

Q: The highest energy level in an atom corresponds ton = _________.

Q: The lowest energy level in an atom is its __________.

Q: The __________ states that a particle cannot be precisely localized.

Q: Two things that are quantized in the Bohr model of the hydrogen atom are __________ and __________.

Q: An atom can be excited into a higher energy state by absorbing a __________.

Q: An excited atom can lose energy by emitting a __________.

Q: A quantum of electromagnetic radiation is a __________.

Q: The __________ occurs when electrons are emitted when light strikes the surface of a metal.

Q: Laser light is ________ and monochromatic, and usually of much ________ intensity than the light from the light bulb.a. coherent b. incoherent c. lowerd. higher

Q: Electrons in atoms a. orbit the nucleus in well defined circular orbits b. radiate electromagnetic energy continuously c. act as if spread out in a "cloud" around the nucleus d. behave as predicted by quantum mechanics

Q: The mathematical model of quantum mechanics was principally founded by a. Max Planck b. Albert Einstein c. Neils Bohr d. Erwin Schroedinger e. Werner Heisenberg.

Q: As the temperature of a blackbody increases, the peak of its radiation curve movesa. upward toward higher intensityb. downward toward lower intensityc. toward larger wavelengthd. toward smaller wavelengthe. none of the above