Name: __________________________ Date: _________________________
Due: Points: 59 points
UNIT 3: Atomic Structure Problem Set 1
1. _________
Which pair must represent atoms of the same element?
1. and 2. and 3. and 4. and 2. _________
Which substance is composed of atoms that all have the same atomic number?
1. magnesium 2. methane 3. ethane 4. ethene 3. _________
All samples of an element are composed of atoms with the same
1. atomic mass 2. atomic number 3. number of nucleons 4. number of neutrons 4. _________
In a sample of pure copper, all atoms have atomic numbers which are
1. the same and the atoms have the same number of electrons
2. the same, but the atoms have a different number of electrons
3. different, but the atoms have the same number of electrons
4. different and the atoms have a different number of electrons
5. _________
In a sample of the element potassium, each atom has
1. 19 protons 2. 20 neutrons
3. 39 protons and neutrons 4. 39 neutrons
6. _________
The atoms in a sample of an element must contain nuclei with the same number of
1. electrons 2. protons
3. neutrons 4. nucleons 7. _________
All the atoms of argon have the same 1. atomic mass
2. atomic number 3. number of neutrons 4. number of nucleons 8. _________
The atomic number of any atom is equal to the number of
1. neutrons in the atom, only 2. protons in the atom, only
3. neutrons plus protons in the atoms 4. protons plus electrons in the atom 9. _________
Two atoms will always have the same atomic number if they have the same
1. mass number 2. number of protons 3. number of neutrons 4. number of nucleons 10. _________
What is the symbol for an atom containing 20 protons and 22 neutrons?
1. 2. 3. 4.
11. _________
Which symbol represents an isotope of carbon? 1.
2. 3. 4.
Which term refers to the region of an atom where an electron is most likely to be found?
1. orbital 2. orbit 3. quantum 4. spectrum 13. _________
Which statement best describes an electron? 1. It has a smaller mass than a proton and a
negative charge.
2. It has a smaller mass than a proton and a positive charge.
3. It has a greater mass than a proton and a negative charge.
4. It has a greater mass than a proton and a positive charge.
14. _________
What is the mass number of an atom which contains 28 protons, 28 electrons and 34 neutrons?
1. 28 2. 56 3. 62 4. 90 15. _________
In an experiment, alpha particles were used to bombard gold foil. As a result of this experiment, the conclusion was made that the nucleus of an atom is
1. smaller than the atom and positively charged 2. smaller than the atom and negatively
charged
3. larger than the atom and positively charged 4. larger than the atom and negatively charged
16. _________
Which particles account for most of the mass of the atom?
1. protons and neutrons 2. protons and electrons 3. neutrons and electrons 4. neutrons and positrons 17. _________
How many protons are in the nucleus of an atom of beryllium?
1. 5 2. 2
3. 9 4. 4 18. _________
Which two atoms are isotopes? 1. and
2. and 3. and 4. and 19. _________
What is a possible mass number of a sodium atom? 1. 1
2. 11 3. 12 4. 23 20. _________
Compared to the entire atom, the nucleus of the atom is
1. smaller and contains most of the atom's mass
2. smaller and contains little of the atom's mass 3. larger and contains most of the atom's mass 4. larger and contains little of the atom's mass 21. _________
All isotopes of a given element must have the same 1. atomic mass
2. atomic number 3. mass number 4. number of neutrons 22. _________
Which particle has a mass of approximately one atomic mass unit and a unit positive charge?
1. a neutron 2. a proton 3. a beta particle 4. an alpha particle 23. _________
An atom of carbon-14 contains
1. 8 protons, 6 neutrons and 6 electrons 2. 6 protons, 6 neutrons and 8 electrons 3. 6 protons, 8 neutrons and 8 electrons 4. 6 protons, 8 neutrons and 6 electrons
24. _________
What is the total number of neutrons in an atom of ?
1. 82 2. 125 3. 207 4. 289 25. _________
What is the total number of protons in the nucleus of an F- ion?
1. 8 2. 9 3. 10 4. 11 26. _________
Rutherford's gold foil experiment illustrated that the atom
1. is mostly empty space
2. is densely packed with electrons 3. cannot be penetrated by any radiation 4. contains a negatively charged nucleus 27. _________
Which atoms represent different isotopes of the same element?
1. and 2. and 3. and 4. and 28. _________
The total number of electrons in a neutral atom of every element is always equal to the atom's
1. mass number 2. number of neutrons 3. number of protons 4. number of nucleons 29. _________
Which atom has a nucleus that contains 13 protons and 14 neutrons?
1. Mg 2. Be 3. Al 4. N
30. _________
A particle of matter contains six protons, seven neutrons, and six electrons. This particle must be a
1. neutral carbon atom 2. neutral nitrogen atom
3. positively charged carbon ion 4. positively charged nitrogen ion 31. _________
Which subatomic particle is found in the nucleus of all isotopes of hydrogen?
1. proton 2. neutron 3. electron 4. positron 32. _________
As the number of neutrons in the nucleus of a given atom of an element increases, the atomic number of that element
1. decreases 2. increases
3. remains the same 33. _________
The characteristic bright-line spectrum of an element is produced when its electrons
1. form a covalent bond 2. form an ionic bond
3. move to a higher energy state 4. return to a lower energy state
34. _________
A substance that is composed only of atoms having the same atomic number is classified as
1. a compound 2. an element
3. a homogeneous mixture 4. a heterogeneous mixture 35. _________
Which symbols represent atoms that are isotopes of each other?
1. 14C and 14N 2. 16O and 18O 3. 131I and 131I 4. 222Rn and 222Ra
36. _________
The atomic mass of an element is defined as the weighted average mass of that element's
1. most abundant isotope 2. least abundant isotope 3. naturally occuring isotopes 4. radioactive isotopes
37. _________
When electrons in an atom in the excited state fall to lower energy levels, energy is
1. absorbed, only 2. released, only
3. neither released nor absorbed 4. both released and absorbed 38. _________
A neutron has approximately the same mass as 1. an alpha particle
2. a beta particle 3. an electron 4. a proton 39. _________
An atom of an element has 28 innermost electrons and 7 outermost electrons. In which period of the Periodic Table is this element located?
1. 5 2. 2 3. 3 4. 4
40. _________
The major portion of an atom's mass consists of 1. electrons and protons
2. electrons and neutrons 3. neutrons and positrons 4. neutrons and protons 41. _________
Which atom contains exactly 15 protons? 1. phosphorus-32
2. sulfur-32 3. oxygen-15 4. nitrogen-15 42. _________
Which atoms contain the same number of neutrons?
1. and 2. and 3. and 4. and 43. _________
An ion with 5 protons, 6 neutrons, and a charge of 3+ has an atomic number of
1. 5 2. 6 3. 8 4. 11 44. _________
Electron X can change to a higher energy level or a lower energy level. Which statement is true of electron X?
1. Electron X emits energy when it changes to a higher energy level.
2. Electron X absorbs energy when it changes to a higher energy level.
3. Electron X absorbs energy when it changes to a lower energy level.
4. Electron X neither emits nor absorbs energy when it changes energy level.
45. _________
Base your answer to the question on the information and the bright-line spectra represented below. Many advertising signs depend on the production of light emissions from gas-filled glass tubes that are subjected to a high-voltage source. When light emissions are passed through a spectroscope, bright-line spectra are produced.
Identify the two gases in the unknown mixture. 1. A and B
2. A and D 3. B and C 4. C and D 46. _________
In the wave-mechanical model, an orbital is a region of space in an atom where there is
1. a high probability of finding an electron 2. a high probability of finding a neutron 3. a circular path in which electrons are found 4. a circular path in which neutrons are found 47. _________
What is the charge of the nucleus in an atom of oxygen-17?
1. 0 2. -2 3. +8 4. +17
48. _________
Which change occurs when a barium atom loses two electrons?
1. It becomes a negative ion and its radius decreases.
2. It becomes a negative ion and its radius increases.
3. It becomes a positive ion and its radius decreases.
4. It becomes a positive ion and its radius increases.
49. _________
How many electrons are contained in an Au3+ ion? 1. 76
2. 79 3. 82 4. 197 50. _________
Which electron configuration represents the electrons of an atom in an excited state?
1. 2-4 2. 2-6 3. 2-7-2 4. 2-8-2 51. _________
In comparison to an atom of in the ground state, an atom of in the ground state has
1. three fewer neutrons
2. three fewer valence electrons 3. three more neutrons
4. three more valence electrons 52.
Base your answer on the data table, which shows three isotopes of neon.
Based on natural abundances, the average atomic mass of neon is closest to which whole number?
53. _________
Which of these phrases best describes an atom? 1. a positive nucleus surrounded by a hard
negative shell
2. a positive nucleus surrounded by a cloud of negative charges
3. a hard sphere with positive particles uniformly embedded
4. a hard sphere with negative particles uniformly embedded
54. _________
Which statement is true about a proton and an electron?
1. They have the same masses and the same charges.
2. They have the same masses and different charges.
3. They have different masses and the same charges.
4. They have different masses and different charges.
55. _________
The atomic mass of an element is the weighted average of the masses of
1. its two most abundant isotopes 2. its two least abundant isotopes 3. all of its naturally occurring isotopes 4. all of its radioactive isotopes
56. _________
Which statement concerning elements is true? 1. Different elements must have different
numbers of isotopes.
2. Different elements must have different numbers of neutrons.
3. All atoms of a given element must have the same mass number.
4. All atoms of a given element must have the same atomic number.
57.
Potassium ions are essential to human health. The movement of dissolved potassium ions, K+(aq), in and out of a nerve cell allows that cell to transmit an electrical impulse.
What is the total number of electrons in a potassium ion?
electrons 58. _________
What is the percent composition by mass of aluminum in Al2(SO4)3 (gram-formula mass = 342 grams/mole)?
1. 7.89% 2. 15.8% 3. 20.8% 4. 36.0%
59.
Base your answer to the question on the information below, which relates the numbers of neutrons and protons for specific nuclides of C, N, Ne, and S.
Using the point plotted on the graph for neon, complete the following table:
Element Number ofProtons Number ofNeutrons NumberMass Nuclide
N 7 9 16 N-16
Ne 10
