What information does a molecular formula provide?
the number and kind of atoms present in a molecule
The molecule formula for the compound hydrogen cyanide is HCN. What information does the molecule formula provide about hydrogen cyanide?
one hydrogen atom, one carbon atom, and one nitrogen atom
Why do atoms share electrons in covalent bonds?
to attain a noble-gas electron configuration
Which noble gas has the same electron configuration as the oxygen in a water molecule?
neon
What is the representative unit in a molecule compound?
a molecule
Which of the following diatomic molecules is joined by a double covalent bond?
O2
When H+ forms a bond with H2O to form the hydronium ion H3O+, this bond is called a coordinate covalent bond because
both bonding electrons come from the oxygen atom
A resonance structure, like the one above, represents
a hybrid of the extremes represented by the resonance forms
The side-by-side overlap of p orbitals produces what kind of bond?
pi bond
Sigma bonds are formed as a result of the overlapping of which type(s) of atomic orbital(s)?
s and p
According to VSEPR theory, molecule adjust their shapes to keep which of the following as far apart as possible?
pairs of valence electrons
What causes water molecules to have a bent shape, according to VSPER theory?
repulsive forces between unshaped pairs of electrons
Experimental evidence suggests that the H-C-H bond angles in ethene, C2H4, are
120 degrees
Which of the forces of molecular attraction is the weakest?
dispersion
What are the weakest attractions between molecules?
Van der Waals forces
Why is hydrogen bonding only possible with hydrogen?
Hydrogen’s nucleus is electron deficient when it bonds with an electronegative atom
What is required in order to melt a network solid?
breaking covalent bonds
The wavelike properties of electrons are useful in
magnifying objects
What are quanta of light called?
photons
What is the number of electrons in the outermost energy level of an oxygen atom?
6
What is the wavelength of an electromagnetic wave that travels at 3 × 108 m/s an has a frequency of 60 MHZ?
300,000,000m/s / 60,000,000 Hz
Which electron configuration of the 4f energy sublevel is the most stable?
4f14
Stable electron configurations are likely to contain
filled energy sublevels
The atomic emission Spectra of a sodium atom on Earth and of a sodium atom in the sun would be
the same
How many unpaired electrons are in a sulfur atom, which has the atomic number 16?
2
What is the maximum number of orbitals in the p sublevel?
3
What is the approximate energy of a photon having a frequency of 4 × 107 Hz?
3×10-26 J
If three electrons are available to fill three empty 2p orbitals, how will the electrons be distributed in the three orbitals?
one electron in each orbital
Which variable is directly proportional to frequency?
energy
What is the approximate frequency of a photon having an energy 5 × 10-24 J?
8 X109 Hz
What is the maximum number of d orbitals in a principal energy level?
5
Which of the following electromagnetic waves have the highest frequencies?
gamma rays
What is the maximum number of d orbitals in any single energy level in an atom?
7
In an s orbital, the probability of finding an electron a particular distance from the nucleus can best be determined by the
quantum mechanical model
Bohr’s model could only explain the spectra of which type of atoms?
single atoms with one electron
How many half-filled orbitals are in a bromine atom?
1
How can the position of a very tiny particle be determined?
by analyzing its interactions with another particle
The quantum mechanical model of the atom
involves the probability of finding an electron in a certain position
Which scientist developed the quantum mechanical model of the atom
Erwin Schrodinger
Which of the following electron configuration of outer sublevels is the most stable?
4d5 5s1
If the spin of one electron in an orbital is clockwise, what is the spin of the other electron in that orbital?
counterclockwise
Who predicted that all matter can behave as waves as well as particles
Louis de Broglie
In Bohr’s model of the atom, where are the electrons and protons located
The electrons move around the protons, which are at the center of the atom
According to the Heisenberg uncertainty principle, if the position of a tiny moving particle is known, the
velocity of the particle cannot be exactly determined
Emission of light from an atom occurs when an electron
drops from a higher to a lower energy level
When an election moves from a lower to a higher energy level, the electron
absorbs a quantum of energy
What is the shape of the 3p atomic orbital?
dumbbell
By the early 1800’s, chemists organizing elements into groups because
there were so many new elements that had been discovered
In which off the following groups of ions are the charges all shown corrrectly
Ca2+, Al3+, Br-
Which of the following decreases with increasing atomic number in Group 2A
ionization energy
Which of the following elements has the smallest atomic radius
chlorine
Which of the following groupings contains only representative elements
Al, Mg, Li
What is another name for the transition metals
Group B elements
Which of the following factors contributes to the increase in ionization energy from left to right across a period?
An increase in the number of protons
Which of the following statements is true about ions
When an anion forms, more electrons are transferred to it
Which of the following elements has the smallest ionic radius
Li
What is the element with the highest electronegativity value
fluorine
Which of the following elements is a transition metal
copper
Which of the following factors contributes to the decrease in ionization energy within a group in the periodic table as the atomic number increases
increases in atomic size
Which of the following elements has the smallest first ionization energy
potassium
What causes the shielding effect to remain constant across a period
electrons are added to the same principal energy level
Which of the following elements has the lowest electronegativity
lithium
Which of the following factors contributes to the increase in atomic size within a group in the periodic table as the atomic number increases
more shielding of the electrons in the highest occupied energy level
Which of the following is true about the electron configurations of the representative elements
The highest occupied s and p sublevels are partially filled
What is the charge of a cation
a positive charge
How does atomic radius change from top to bottom in a group in the periodic table
It tends to increase
Atomic size generally
decreases as you move from left to right across a period
What is another name for the representative elements
Group A elements
Which of the following is true abut the electron configurations of the noble gases
the highest occupied s and p sublevels are completely filled
The atomic number of an element is the total number of which particles in the nucleus
protons
Which of the following electron configurations is most likely to result in an element that is relatively inactive
a filled highest occupied principal energy level
What is the element with the lowest electronegativity value
cesium
Which of the following categories includes the majority of the elements
metals
Which statement is true about electronegativity
Electronegativity generally increases from left to right across a period
Of the elements Fe, Hg, U, and Te, which is a representative element
Te
As you move from left to right across the second period of the periodic table
ionization energy increases
in which of the following sets are the charges given correctly for all the ions
K+, Sr2+, O2-
Of the following elements, which one has the smallest first ionization energy
aluminum
Which subatomic particle plays the greatest part in determining the properties of an element
electron
Which of the following statements correctly compares the relative size of an ion to its neutral atom
the radius of an anion is greater than the radius of its neutral atom
What are the Group 1A and Group 7A elements examples of
represenative elements
What is the energy required to remove an electron from the atom in the gaseous state called
ionization energy
Which of the following statements is true about ions
Catons form when an atom loses electrons
In which of the following sets is the symbol of the element, the number of protons, and the number of electrons given correctly
In, 49 portons, 49 electrons
How many valence electrons are in an atom of phosphorus
5
How many valence electrons does a helium atom have
2
What is the name given to the electrons in the highest occupied energy level of an atom
valence electrons
How many electrons does barium have to give up to achive a noble-gas electron configuration
2
Which of the following ions has a pseudo-noble-gas configuration
Cu+
Which of the following is a pseudo-noble-gas electron configuration
1s22s22p63s23p63d10
What is the formula of the ion formed when phosphorus achieves a noble-gas configuration
p3-
What is the elctron configuraation of the iodide ion
1s22s22p63s23p63d104s24p64d105s25p6
How many valence electrons are transferred from the nitrogen atom to potassium in the formation of the compound potassium nitride
0
What is the formula unit of sodium nitride
Na3N
Alloys with a wide range of use are referred to as
steels
Alloys are commonly used in manufacturing. Which if the following is a reason to use alloy instead of a pure metal
Bronze is tougher than pure copper
Which of the following pairs of elements is most likely to form an ionic compound
magnesium and fluorine
Which of the following is trueabout the melting temp of potassium chloride
The melting temp is relativily high
Under what conditions can potassium bromide conduct electricity
only when melted or dissolved in water
Wt characteristics of metals makes them good electrical conductors
they have mobile valence electrons