Which one of the following is not one of the postulates of Dalton's atomic theory?
Atoms are composed of protons, neutrons, and electrons
Which statement below correctly describes the responses of alpha, beta, and gamma radiation to
an electric field?
Alpha and beta are deflected in opposite directions, while gamma shows no response
In the Rutherford nuclear-atom model, __________.
the heavy subatomic particles, protons and neutrons, reside in the nucleus
There are __________ electrons, __________ protons, and __________ neutrons in an atom of
54, 54, 78
An atom of the most common isotope of gold, 197Au, has __________ protons, __________
neutrons, and __________ electrons
79, 118, 79
The atomic mass unit is presently based on assigning an exact integral mass (in amu) to an isotope
The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the
isotopes are given in the table below. The average atomic mass of the element is __________ amu
The average atomic weight of copper, which has two naturally occurring isotopes, is 63.5. One of
the isotopes has an atomic weight of 62.9 amu and constitutes 69.1% of the copper isotopes. The
other isotope has an abundance of 30.9%. The atomic weight (amu) of the second isotope is
Which pair of elements would you expect to exhibit the greatest similarity in their physical and
The elements in groups 1A, 6A, and 7A are called, __________, respectively.
alkali metals, chalcogens, and halogens
There are __________ protons, __________ neutrons, and __________ electrons in 131I-.
53, 78, and 54
) Aluminum reacts with a certain nonmetallic element to form a compound with the general
formula Al2X3. Element X must be from Group __________ of the Periodic Table of Elements.
The wavelength of light emitted from a traffic light having a frequency of 5.75 x 1014 Hz is
Of the following transitions in the Bohr hydrogen atom, the __________ transition results in the
emission of the highest-energy photon.
n = 6 → n = 1
According to the Heisenberg Uncertainty Principle, it is impossible to know precisely both the
position and the __________ of an electron
All of the orbitals in a given subshell have the same value of the __________ quantum number.
A and B
magnetic and principal
Which one of the following is not a valid value for the magnetic quantum number of an electron in
a 5d subshell?
An electron cannot have the quantum numbers n = __________, l = __________, ml = __________.
1, 1, 1
Which quantum numbers must be the same for the orbitals that they designate to be degenerate in
a one-electron system (such as hydrogen)?
In a px orbital, the subscript x denotes the __________ of the electron
axis along which the orbital is aligned
At maximum, an f-subshell can hold __________ electrons, a d-subshell can hold __________
electrons, and a p-subshell can hold __________ electrons.
14, 10, 6
Which electron configuration represents a violation of the Pauli exclusion principle?
1s: ^ v
2s: ^ ^
Which one of the following is the correct electron configuration for a ground-state nitrogen atom?
1s: ^ v
2s: ^ v
2p: ^ ^ ^
Which electron configuration represents a violation of Hund's rule for an atom in its ground state?
1s: ^ v
2s: ^ v
2p: ^ v
The lowest orbital energy is reached when the number of electrons with the same spin is
maximized. This statement describes __________.
The atomic radius of main-group elements generally increases down a group because __________.
the principal quantum number of the valence orbitals increases
Of the following, which gives the correct order for atomic radius for Mg, Na, P, Si and Ar?
Na > Mg > Si > P > Ar
Which of the following correctly represents the second ionization of phosphorus?
P+ (g) → P2+ (g) + e-
In the generation of most anions, the energy change (kJ/mol) that _______ an electron is ________.
The largest principal quantum number in the ground state electron configuration of
francium is __________.
The electron configuration of the valence electrons of an atom in its ground state is ns2n
p3. This atom is a group __________ element.
All of the subshells in a given shell have the same energy in the hydrogen atom. In a many-electron atom, the
subshells in a given shell do not have the same energy. Why?
Hydrogen atoms have only one electron. Therefore, in a hydrogen atom, the energy of orbitals depends only on n. In
many-electron atoms, electron-electron repulsion causes the energies of subshells in a given shell to differ.