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Alberta Diploma Exams The Atom — practice questions

Explore 26 free The Atom questions in Alberta Diploma Exams Physics. Open each question or exercise to read its content, reference answers and available explanation.

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The Atom questions and exercises with answers

Showing questions 1–26 of 26.

About how many alpha particles were scattered straight backward in Rutherford's gold foil experiment?Read the answer and worked solution →What are the dark lines seen in the absorption spectrum of the sun called?Read the answer and worked solution →Electrons dropping from higher orbits to the n = 1 ground state of hydrogen produce which spectral series?Read the answer and worked solution →How much energy must a hydrogen atom's electron absorb to jump from the ground state (n = 1) to the second orbital (n = 2)? Use En = -13.6 eV / n^2.Read the answer and worked solution →What are protons and neutrons collectively called?Read the answer and worked solution →What does the atomic number Z represent?Read the answer and worked solution →The atomic mass unit (u) is defined so that a neutral atom of which isotope has a mass of exactly 12 u?Read the answer and worked solution →What holds the protons and neutrons of a nucleus together despite the mutual repulsion between protons?Read the answer and worked solution →The nuclear radius formula is r = r0 A^(1/3), with r0 = 1.2 femtometres. What is the radius of an aluminum-27 nucleus?Read the answer and worked solution →During alpha decay, what does a nucleus emit?Read the answer and worked solution →During beta-minus decay, a neutron transforms into which combination of particles?Read the answer and worked solution →Beta decay producing barium-137 comes from which parent nucleus? Barium has atomic number 56.Read the answer and worked solution →Which type of radiation has the shortest range, being stopped by a sheet of paper or a fraction of a millimetre of tissue?Read the answer and worked solution →What is the half-life of a radioactive sample?Read the answer and worked solution →How is the decay constant, lambda, related to the half-life, t(1/2)?Read the answer and worked solution →Iodine-131 has a half-life of 8.02 days. What is its decay constant, lambda, in units of per day?Read the answer and worked solution →An 800 g sample of a radioactive isotope has a half-life of 15.0 minutes. How much of the original sample remains after 45.0 minutes?Read the answer and worked solution →Carbon-11 has a half-life of 20.334 minutes. Starting from a 1000 g sample, about how much remains after exactly one hour (about three half-lives)?Read the answer and worked solution →What is the SI unit for activity, defined as one decay per second?Read the answer and worked solution →The curie (Ci) was originally defined as the activity of what quantity of radium-226?Read the answer and worked solution →Between uranium-235 and plutonium-239, which nuclide has the smaller critical mass?Read the answer and worked solution →About how much energy does the average nuclear fission reaction release?Read the answer and worked solution →Fission of 1.00 kg of uranium-235 releases about 8.21 x 10^13 J, given 200 MeV per fission event. About how many uranium-235 atoms are in 1.00 kg?Read the answer and worked solution →What is the main obstacle that must be overcome to make two light nuclei fuse together?Read the answer and worked solution →What is a radiopharmaceutical?Read the answer and worked solution →The same 1.00 J of ionizing energy from the previous scenario is instead absorbed only by a 2.00 kg forearm. What is the dose to the forearm, in rad?Read the answer and worked solution →

Worked practice questions

About how many alpha particles were scattered straight backward in Rutherford's gold foil experiment?

  1. 1 in 8 particles
  2. 1 in 800 particles
  3. 1 in 8,000 particles
  4. 1 in 8,000,000 particles
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Correct answer: C. 1 in 8,000 particles

1. Rutherford's experiment showed that only a small fraction of alpha particles scattered straight back. 2. That fraction is given as 1 in 8,000 particles. 3. 1 in 8 or 1 in 800 would suggest far too much backscattering for a mostly empty atom. 4. 1 in 8,000,000 is far smaller than the fraction actually reported. 5. So 1 in 8,000 is correct. _Source: OpenStax Physics (CC BY 4.0), Ch 22 "The Atom", section 22.1 The Structure of the Atom_

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What are the dark lines seen in the absorption spectrum of the sun called?

  1. Rydberg lines
  2. Rutherford lines
  3. Balmer lines
  4. Fraunhofer lines
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Correct answer: D. Fraunhofer lines

1. The sun's absorption spectrum shows dark lines where certain wavelengths have been absorbed by gases in its exterior. 2. Those dark lines are called Fraunhofer lines. 3. The Rydberg constant and Balmer series are related to hydrogen's emission spectrum, not named for these dark absorption lines. 4. Rutherford lines is not a term used for any spectral feature here. 5. So Fraunhofer lines is correct. _Source: OpenStax Physics (CC BY 4.0), Ch 22 "The Atom", section 22.1 The Structure of the Atom_

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Electrons dropping from higher orbits to the n = 1 ground state of hydrogen produce which spectral series?

  1. The Lyman series
  2. The Balmer series
  3. The Paschen series
  4. The Fraunhofer series
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Correct answer: A. The Lyman series

1. Each spectral series is named for the orbital level electrons drop into. 2. The Lyman series comes from electrons dropping all the way to the ground state, n = 1. 3. The Balmer series instead comes from electrons dropping to n = 2, and the Paschen series comes from dropping to n = 3. 4. Fraunhofer is not the name of an emission series at all. 5. So the Lyman series is correct. _Source: OpenStax Physics (CC BY 4.0), Ch 22 "The Atom", section 22.1 The Structure of the Atom_

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More Physics topics

Postulates of Special RelativitySpecial RelativityNuclear Fission and FusionNuclear Forces and RadioactivityHalf Life and Radiometric Dating