Chemistry Midterm Review (Unit 3 and Unit 4)
Tritium (3H) is used in glowing "EXIT" signs located where there is no electricity for light bulbs. What fraction of the original quantity of the isotope is left in the sign after approximately 49.25 years?
1/16
What is the maximum number of electrons that can fill all the orbitals of a f sublevel?
14 electrons
How many orbitals are in the n = 2 shell.
4
The notation for the subshell with n = 4 and l = 2 is...
4d subshell
How many pairs of electrons are present in the 3d subshell in the ground state electron configuration of the Cu atom?
5
Uranium-238 decays to form thorium-234. How many years will it take for 75% of the uranium-238 to decay?
8.94 × 109 years
Beta emission is associated with __________ . a) conversion of a neutron to a proton b) conversion of a proton to a neutron c) increase in mass number d) decrease in mass number by 4 and atomic number by 2 e) emission of γ rays
A
The letter designated to represent the electron subshell in an atom is a) the secondary quantum number, l. b) the principal quantum number, n. c) the magnetic quantum number, ml. d) the spin quantum number, ms. e) the transverse polarization of the optical emission from the H atom.
A
What is the frequency of radiation which has an energy of 3.371 × 10-19 Joules per photon? a) 5.088 x 1014 s-1 b) 1.966 x 10-15 s-1 c) 2.234 x 10-52 s-1 d) 6.626 x10-34 s-1 e) 8.899 x 1026 s-1
A
What is the shell configuration of electrons for neutral atoms of nickel, 28Ni, in the ground state? a) 2-8-16-2 b) 2-8-10-8 c) 2-8-8-10 d) 2-18-8-0 e) 2-8-16-28
A
Which element requires the least amount of energy to remove its most loosely bound electron? a) Rb b) Na c) Al d) Ne e) O
A
Which sequence represents a correct order of historical developments leading to the modern model of the atom? a) the atom is a hard sphere → most of the atom is empty space → electrons exist in orbitals outside the nucleus b) the atom is a hard sphere → electrons exist in orbitals outside the nucleus → most of the atom is empty space c) most of the atom is empty space → electrons exist in orbitals outside the nucleus → the atom is a hard sphere d) most of the atom is empty space → the atom is a hard sphere → electrons exist in orbitals outside the nucleus
A
According to the Bohr Model of the atom, atoms can only absorb energy at certain wavelengths because a) Atoms of different elements contain different numbers of protons b) Electrons only exist in certain energy levels c) Most of the atom contains empty space d) Atoms of different elements contain different numbers of electrons
B
Nuclear fission produces energy because __________ . a) neutrons are produced b) the total mass of the products is less than that of the reactants c) the total mass of the products is more than that of the reactants d) it is a very powerful chemical reaction e) photons are produced
B
Which of the following gives a possible quantum number assignment for the last electron added to the sulfur atom when developing the electron configuration using the aufbau principle? n l ml ms a) 2 1 +1 ½ b) 3 1 0 ½ c) 3 0 0 ½ d) 3 2 +1 ½ e) 4 1 -1 0
B
Which type of radiation has the greatest penetration ability? a) α b) γ c) n d) β- e) β+
B
Which element has the strongest attraction for electrons? a) Krypton b) Hydrogen c) Oxygen d) Francium e) Calcium
C
Which nuclide is paired with a specific use of that nuclide? a) carbon-14, treatment of cancer b) uranium-238, dating of once-living organisms c) iodine-131, treatment of thyroid disorders d) cobalt-60, dating of rock formations
C
Which one of the following statements is not correct? a) Carbon-10 is unstable because it has too few neutrons. b) All nuclides with an atomic number > 83 decay into nuclides with smaller nuclear charges. c) Generally, the number of neutrons in a nuclide is equal to or less than the atomic number. d) As the atomic number increases, the ratio of neutrons to protons in a nuclide increases.
C
Which statement is true concerning the spectrum of hydrogen obtained from a gas discharge tube? a) A photon is absorbed as the electron goes from a state with a higher energy to one with a lower energy. b) An electron is absorbed as a photon goes from a state with a lower energy to one with a higher energy. c) A photon is emitted as the electron goes from a state with a higher energy to one with a lower energy. d) An electron is emitted as a photon goes from a state with a lower energy to one with a higher energy.
C
A radioactive-dating procedure to determine the age of a mineral compares the mineral's remaining amounts of isotope 238U and isotope a) Lead-214 b) Bismuth-214 c) Bismuth-206 d) Lead-206
D
A sample of which radioisotope emits particles having the greatest mass? a) H-3 b) Cs-137 c) Fe-53 d) Fr-220
D
Given the following sets of quantum numbers for n, l, ml, and ms, which one of these sets is not possible for an electron in an atom? n l ml ms a) 3 2 +2 ½ b) 3 1 1 ½ c) 4 3 2 ½ d) 4 4 +3 ½ e) 5 2 -2 ½
D
Nitrogen-12 is most likely to decay by __________ . a) gamma emission b) beta emission c) alpha emission d) either positron emission or electron capture
D
The Pauli principle states that a) an electron in an atom can move to another energy level. b) the energy of an electron has a specific quantum number. c) the electron trapped in an atom has particle characteristics. d) no two electrons in the same atom can have all their quantum numbers the same. e) an orbital can hold as many electrons as possible.
D
The isotope Cr-53 is produced by the beta decay of which of the following: a) 53Mn b) 54Cr c) 52Cr d) 53V e) 54V
D
Which of the following statements is false? a) U-238 is unstable, as expected based on the fact that it's nuclear charge is greater than Bismuth's. b) N-16 is unstable and radioactive because its neutron/proton ratio is too high. c) Nuclear reactions often produce large amounts of energy because small amounts of mass are converted into energy. d) All radioactive isotopes decay completely and disappear within a short time (1 year or less).
D
Which pair of nuclei can undergo a fusion reaction? a) potassium-40 and cadmium-113 b) zinc-64 and calcium-44 c) uranium-238 and plutonium-239 d) hydrogen-2 and hydrogen-3 e) potassium-40 and magnesium-24
D
Which configuration represents an alkaline earth element? a) [Ar] 4s1 3d5 b) [Ar] 4s2 3d4 c) [Xe] 5s2 5p1 d) [Xe] 6s2 4f6 e) [Rn] 7s2
E
Which of the following postulates from Dalton's atomic theory are now considered incorrect? I. All the atoms of a given element are identical. II. Matter consists of very small particles known as atoms. III. Atoms are indestructible and also indivisible. a) III only b) II only c) I only d) I and II e) I and III
E
The person who first postulated the concept of the nuclear atom was...
Ernest Rutherford
Radioisotopes used for medical diagnosis must have...
Short half-lives that can be quickly emitted by the body
Control rods in nuclear reactors are commonly made of boron and cadmium because these two elements have the ability to...
absorb neutrons
The nucleus of a radium-226 atom is unstable, which causes the nucleus to spontaneously...
decay
As a sample of a radioactive element decays, its half-life...
remains the same
All orbitals with the same value of the principal quantum number and the secondary quantum number are said to belong to the same...
sublevel
ground state electron configuration
the lowest energy arrangement of the electrons for each element
Which emanation is attracted toward a negatively charged electrode?
α (alpha)
