chem unit 1 and 2
the photoelectron spectra of the 1s electrons of two isoelectronic species Ca+2 and Ar, are shown above. Which of the following correctly identifies the species associated with peak X and provided vaid justification?
Ca2+ because its nuclear has two more protons than the nucleus of Ar has
forms monoatomic ions with 2^- charge in solutions
S
in which of the following groups are the three species isoelectronic
S-2, K+, Ca2+
consider atoms of the following elements. Assume that the atoms are in the ground state. The atom that contains exactly 3 unpaired electrons
Sb
which electron in sulfur is most shielded from nuclear charge
an electron in the 3p orbital
lewis electron dot diagrams for CO2 and SO2 are given above. The molecular geometries and polarity of the two substances are
different because the lone pair of electrons on the S atom make it the negative end of a dipole
which of the following correctly indicates whether the solid represented by the particle model shown to the left conducts electricity and explains why or why not?
it does not conduct electricity because its ions cannot move freely within the solid.
In the reaction represented above, what is the hybridization of the C atoms before and after the reaction occurs
sp2, sp3
which of the following is true of the halogens when comparing them to other elements in the same period
they have a higher ionization energy than elements within their period
the element is known to form more than one oxide. which pair of formulas included the two most likely formulas of these oxides?
GeO and GeO2
two different ionic compounds each contain only copper and chlorine. both compounds are powders one white and one brown. an element analysis is performed on each powder. which of the following questions about the compounds is most likely to be answered by the result of the analysis
what is the formula unit of each compund?
which of the following lewis diagrams best represents the bonding in the N2O molecule considering formal charges
(Actual picture of the Lewis structure) 2NIIINI6O
the ionization energies for an element are listed below. Based on the table above, the element is most likely
(chart)carbon
which of the following complete lewis diagrams represent a molecule containing a bond angle that is closest to 120 degrees
(diagram answer) 4H2C3O
Which of the following is not a valid resonance structure for N3-?
(diagram) 4NII2NI6N
choose the electron dot formula that most accurately describes the bonding in CS2
(diagram) 4SII4CII4S
steel is an alloy containing Fe atoms and C atoms. Which of the following diagrams represents the particle level structure of steel
(diagram) Large Fe Small C atoms
the mass spectrum of the element Sb is most likely represented by which of the following
(graph) 121 and 123
The photoelectron spectrum of the element given to the left. Which of the following electron configurations is consistent with the spectrum
(graph)1s2 2s2
the ground state electron configuration of Ni2+ is which of the following?
1s2, 2s2, 2p6, 3s2, 3p6, 3d8
how many carbon atoms are contained in 2.8 grams of C2H4
1.2x10^24
which of the following ground state electron configurations represent the atom that has the lowest first ionization energy
1s2 2s2 2p6 3s1
How many resonance structures can be drawn for O3?
2
A 6.0 sample of C3H8(g) and 20 mol sample of Cl2(g) are places in previously evacuated vessel, where they react according to the equation above. After one of the reactants has been totally consumed, how many moles of HCl (g) have been produced?
20. mols
How many protons, neutrons, and electrons are in 56 26 Fe atom
26, 30, 26
which of the following correctly identifies which has a higher first ionization energy, Cl or Ar, and supplies the best justification?
Ar because of its higher effective nuclear charge
atoms of Mg combine withe atoms of F to form a compound. atoms of which of the following elements combine with atoms of F in the same ratio
Ba
a 23.0g sample of a compound contains 12.0g of c 3.0g and 8.0g O. which of the following is an empirical formula of the compound
C2H6O
the electron pair in a C-F bond could be considered
Closer to F because Fluorine has a higher electronegativity than carbon.
The potential energy as a function of internuclear distance for three diatomic molecules, X2 Y2 Z2, is shown in the graph to the right. Based on the data in the graph, which of the following correctly identifies the diatomic molecules X2, Y2, Z2?
H2, N2, O2
two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. which of the following is the most valid scientific claim that can be made about the compound.
It contains iconic bonds
the lattice energy of a salt is related to the energy required to separate the ions. for which of the following pairs of ions is the energy that is required to sperate ions largest
Mg+2 and O-2
atoms of element x have the electron configuration shown below. 1s2 2s2 2p6 3s2 3p3. The compound most likely formed with magnesium, Mg, is
Mg3X2
which of the following atoms cannot exceed the octet rule in a molecule
N
which of the following has an incomplete octet in its lewis structure
NO
which has the greater bond length, No2- or NO3-?
NO3-
when placed in order of decreasing ionization energy (highest to lowest), what is the correct order for the species O, O+, and O-?
O-, O, O+
which of the following has a bond order of 2
O2
Which of the following molecules has a dipole moment?
PF3
The potential energy system of two atoms as a function of their internuclear distance is shown in the diagram above. which of the following is true regarding the force between the atoms when their internuclear distance is x.
The attractive and repulsive forces are balanced, so the atoms will maintain an average internuclear distance x
which of the following scientific claims about the bond in the molecular compound in HF is most likely to be true
The bond is highly polar
The elements C and Se have the same electronegativity value, 2.55. Which of the following claims about the compound that forms the C and Se is most likely to be true?
The carbon to selenium bond is nonpolar covalent
The energy required to dissociate an ionic solid into gaseous ions (lattice energy) for the compounds NaF and MgF2 is shown in the table above. On the basis f coulombs law. which of the following best helps explain the large difference between the lattice energies of NaF and MgF2
The charge of the Mg cation is larger than that of the Na cation
Which of the following best helps explain why the electronegativity of Cl is less than that of F?
When CL and F form bonds with other atoms, The cl bonding electrons are more shielded from the positive Cl nucleus than the F bonding electrons are shielded from the positive F nucleus.
which of the following atoms or ions has exactly two unpaired electrons
Zr2+
copper and zinc atoms have the same atomic radius 135 picometers. based on this information, which of the following diagrams best represent an alloy containing only copper and zinc atoms.
even atoms all in a straight line and straight columns and all identical.
The complete photoelectron spectrum for an element is shown to the left. Which of the following observations would provide evidence that the spectrum is consistent with the atomic model of the element
in its compound the elements tend to form ions with a charge of +3
a student obtains a sample of a pure solid compound. In addition to avogadros number, which of the following must the student know in order to determine how many molecules are in the sample
molar mass of the compound, mass of the sample
which of the following represents a general electron configuration that corresponds to the valence electrons of an element for which there is an especially large jump between the third and fourth ionization energies
ns2np1
The Bf3 molecule is nonpolar, whereas the NF3 molecule is polar. Which of the following statements accounts for the diffrence in polarity of the two molecules?
unlike BF3 NF3 has a nonpolar geometry due to an unshared pair of electrons on the N atom
