Q&A Hero

Q: The most important force in the hydrogen atom is A) the nuclear force. B) the gravitational force. C) the electromagnetic force. D) none of these.

Q: When an electron goes from the ground state to an excited state, A) energy is emitted. B) a photon is absorbed. C) a photon is emitted. D) none of these occur.

Q: When an electron goes from an excited state to the ground state, A) energy is absorbed. B) a photon is absorbed. C) a photon is emitted. D) none of these occur.

Q: When a hydrogen electron is in its ground state, its principal quantum number is A) zero. B) "13.6 eV. C) 1. D) +13.6 eV. E) none of these.

Q: How much energy must be absorbed to ionize a hydrogen atom whose electron is in the ground state (n= 1)? A) Zero B) 1 eV C) 0.053 eV D) 13.6 eV

Q: Which is nota possible value for the principal quantum number n? A) 3 B) 7 C) 3/2 D) None of these

Q: Which is a possible value for the principal quantum number n? A) 3.14 B) 7 C) 2.5 D) None of these

Q: The lowest energy level of a hydrogen atom (n= 1) is called A) the ground state. B) the potential state. C) the ionization state. D) none of these.

Q: The removal of an electron from an atom is called A) binding affinity. B) atomizing. C) electron affinity. D) ionization.

Q: In terms of energy levels of electrons, a potential well has A) a negative value. B) a positive or a negative value. C) a positive value. D) none of these.

Q: When an electron in an atom is excited from a lower energy level to a higher one, a ______________ is ______________. A) proton; absorbed B) proton; emitted C) photon; absorbed D) photon; emitted

Q: When an electron in an atom falls from a higher energy level to a lower one, a ______________ is ______________. A) proton; absorbed B) proton; emitted C) photon; absorbed D) photon; emitted

Q: Fluorescence occurs when samples of some materials are exposed to rays of which EMR region? A) Ultraviolet B) Infrared C) Visible D) Microwave

Q: The lines in the visible region of the hydrogen spectrum arise from transitions from higher levels back to the level where nequals A) 3. B) 1. C) 2. D) 4.

Q: The transitions of an electron in the hydrogen atom to the n = 3 level result in the A) Lyman series. B) Balmer series. C) Paschen series. D) Bohr series.

Q: The transitions of an electron in the hydrogen atom to the n = 2 level result in the A) Lyman series. B) Balmer series. C) Paschen series. D) Bohr series.

Q: The transitions of an electron in the hydrogen atom to the n = 1 level result in the A) Lyman series. B) Balmer series. C) Paschen series. D) Bohr series.

Q: The lines in the visible region of the hydrogen spectrum are known as the A) Lyman series. B) Balmer series. C) Paschen series. D) Bohr series.

Q: Niels Bohr focused his attention on the element hydrogen because it A) could be obtained in extremely high purity. B) was so abundant. C) had the simplest atom. D) was inexpensive.

Q: Discrete wavelengths of light are emitted by an excited gas because A) the speed of light is constant in a given medium. B) light can behave either as a wave or as a particle. C) electron energy levels are quantized. D) the intensity of radiation is proportional to the second power of the frequency.

Q: If the energy of n= 3 is -1.51 eV and that of n= 4 is -0.85 eV in a hydrogen atom, a transition from n= 3 to n= 4 will _______________ a photon with an energy of approximately ______________.A) emit; 2.36 eVB) absorb; 0.661 eVC) emit; 0.661 eVD) absorb; 2.36 eV

Q: Calculate the energy En(in eV) of a hydrogen atom's electron with n= 4.A) -54 eVB) -3.4 eVC) -0.85 eVD) -1.7 eV

Q: For a specific element, photons of how many different energies could be emitted by electrons in the n= 6 level as they return to the n= 1 level? A) 15 B) 21 C) 6 D) 1

Q: For a specific element, photons of how many different energies could be emitted by electrons in the n= 3 level as they return to the n= 1 level? A) 1 B) 4 C) 2 D) 3

Q: For a specific element, photons of how many different energies could be emitted by electrons in the n= 2 level as they return to the n= 1 level? A) 3 B) 4 C) 2 D) 1

Q: The calculation of electron energy levels in the hydrogen atom was done first by A) Schrdinger. B) de Broglie. C) Bohr. D) Heisenberg.

Q: Dispersing light that has traveled from a hot wire through a cool gas gives what type of spectrum? A) Line absorption B) Continuous C) Line emission D) Ultraviolet

Q: Dispersing light from a hot wire gives what type of spectrum? A) Line absorption B) Continuous C) Line emission D) Ultraviolet

Q: Who developed the quantum theory in 1900 and has a constant named for him? A) de Broglie B) Bohr C) Planck D) Einstein

Q: Einstein won the Nobel Prize for explaining A) general relativity. B) special relativity. C) the photoelectric effect. D) quantum mechanics.

Q: Who won the Nobel Prize for explaining the photoelectric effect? A) Bohr B) Planck C) de Broglie D) Einstein

Q: A quantum is a A) discrete amount. B) fundamental property. C) unit of momentum. D) proton.

Q: Which of these colors of light has photons of lowestenergy? A) Yellow B) Green C) Blue D) Violet

Q: Which of these colors of light has photons of lowestenergy? A) Blue B) Green C) Yellow D) Violet

Q: Which of these colors of light has photons of lowestenergy? A) Blue B) Green C) Yellow D) Red

Q: What is the energy of a photon with a frequency of 5.2 x 1014Hz?A) 3.4 x 10-19JB) 1.3 x 10-20JC) 0.8 x 10-20JD) 0.3 x 10-21J

Q: Calculate the frequency in hertz of photons of light with energy of 9.90 x 10-19 J.A) 0.67 x 1014HzB) 0.67 x 1015HzC) 1.49 x 1015HzD) 1.49 x 1014Hz

Q: Which of these colors of light has photons of greatest energy? A) Red B) Orange C) Green D) Yellow

Q: Which of these colors of light has photons of greatest energy? A) Violet B) Red C) Blue D) Yellow

Q: Which of these colors of light has photons of greatest energy? A) Green B) Red C) Blue D) Yellow

Q: The greater the frequency of light, the greater the ______________ of its photons. A) velocity B) speed C) wavelength D) energy

Q: According to Planck's hypothesis, the energy of an oscillator is directly proportional to its A) amplitude. B) wavelength. C) momentum. D) frequency.

Q: The number of electrons in an atom of an element is the same as the element's A) atomic number. B) period number. C) mass number. D) group number.

Q: Addition of an electron to an atom leaves a A) neutron. B) positive ion. C) free quark. D) negative ion.

Q: Removal of an electron from an atom leaves a A) neutron. B) positive ion. C) free quark. D) negative ion.

Q: Aristotle's "continuous" model of matter was proved wrong about 1807 by A) Bohr. B) Thomson. C) Dalton. D) Rutherford.

Q: Atomic physics deals mainly with phenomena involving which particles in atoms? A) Quarks B) Protons C) Electrons D) Neutrons

Q: The development of physics since about 1900 is called A) neoclassical physics. B) Newtonian physics. C) classical physics. D) modern physics.

Q: The "plum pudding model" of the atom is associated with A) Bohr. B) Rutherford. C) Dalton. D) Thomson.

Q: The ""billiard ball model" of the atom is associated with A) Bohr. B) Thomson. C) Rutherford. D) Dalton.

Q: The voltage in a house is measured to be 122.5 V. What is the current drawn by a 75.0-W light bulb?

Q: A doorbell has an input voltage of 120 V. A transformer that steps the voltage down to 12 V has 500 turns on its primary. What is the number of turns on the secondary?

Q: A transformer with 800 turns on the primary coil is used to decrease the voltage from 2000 V to 120 V for home use. How many turns should be in the secondary coil?

Q: A 10-Wresistor and a 20-Wresistor are connected in parallel, and this combination is connected in series to a 30-Wresistor. If the arrangement is hooked to a 12-V battery, how much current flows in the circuit?

Q: Three resistors, 10 W, 20 W, and 30 W, are wired in parallel and connected to a 12-V battery. How much current flows in the circuit?

Q: A 20-Wresistor and a 30-Wresistor are wired in parallel and connected to a 9.0-V battery. a. How much current is drawn from the battery? b. How much power is dissipated in the circuit?

Q: In a 12-V battery circuit, a 10-Wresistor and a 30-Wresistor are connected in series. How much current does the battery supply to the circuit?

Q: A current of 6.0 A flows through a resistance of 50 W. How much power is dissipated?

Q: A component in an automobile 12-V electrical system has a resistance of 20 W. a. How much current is in the component when the system is in operation? b. How much energy is dissipated by the component each second?

Q: A steady current of 0.15 A exists in a wire for 20 s.a. How much net charge passes by a point in the wire?b. How many electrons does this charge represent?

Q: If two protons are moved 3 times closer together, the electrical force between them is what factor of the original force?

Q: If two protons are moved 3 times farther apart, the electrical force between them is what factor of the original force?

Q: An insulator has a positive electric charge of 2.4 x 10-17C. How many electrons were added or removed?

Q: Three resistors, 10 W, 20 W, and 30 W, are wired in series and connected to a 120-V battery. How much current flows in the circuit?

Q: AC voltage may be stepped up or stepped down using a(n) ______________.

Q: A step-down transformer has more windings on the ________ coil.

Q: In a dc motor, the polarity and current are reversed by a(n) __________.

Q: A(n) __________ converts electrical energy into mechanical energy.

Q: A(n) ______________ converts mechanical energy into electrical energy.

Q: A moving electric charge or a current in a magnetic field may experience a(n) ______________.

Q: A ferromagnetic material loses this property above the ______________ temperature.

Q: The north pole of a compass points toward Earth's magnetic ______________ pole.

Q: Magnetic fields can deflect ______________ charges.

Q: The law of poles states that like magnetic poles ______________ and unlike magnetic poles ______________.

Q: According to the law of poles, like poles ______________.

Q: Zero potential in household electricity is called ______________.

Q: A circuit breaker is connected in ______________ in a circuit.

Q: The voltage for typical home appliances is ______________.

Q: To prevent a home electric circuit from overheating because of too much current, a(n) ______________ is used.

Q: The maximum current would flow in a set of resistors connected in ______________.