Chemistry Comp Review
A nonpolar covalent bond is most likely to form between two elements that have a difference in electronegativity values of
0.1
The number of valence electrons in Group 1 elements is
1
A polar covalent bond is most likely to form between two elements that have a difference in electronegativity values of
1.5
The elements whose electron configurations end with s2 p5 in the highest occupied energy level belong to Group
17
Chlorine has atomic number 17 and mass number 35. It has
17 protons, 17 electrons, and 18 neutrons
Phosphorus-33 (atomic number 15) contains
18 neutrons
What is the electron configuration for nitrogen, atomic number 7?
1s2 2s2 2p3
The electron notation for aluminum (atomic number 13) is
1s2 2s2 2p6 3s2 3p1
The spin quantum number indicates that the number of possible spin states for an electron in an orbital is
2
Determine the number of moles of helium in 10.0 g of helium. The molar mass of helium is 4.00 g/mol.
2.5 moles
An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is
27
The electron configuration of aluminum, atomic number 13, is [Ne] 3s2 3p1. Aluminum is in Period
3
The electron configuration for nitrogen is 1s2 2s2 2p3. What does the 3 in 2p3 mean?
3 electrons
The molar mass of H2O is 18.02 g/mol. How many grams of H2O are present in 0.20 mol?
3.6 g
How many electrons are needed to completely fill the fourth energy level?
32
The mass of 2.0 mol of oxygen atoms (atomic mass 16.00 amu) is
32 g
What is the mass of 0.240 mol glucose, C6H12O6?
43.2 g
What is the mass percentage of OH- in Ca(OH)2?
45.9%
What is the formula mass of ethyl alcohol, C2H5OH?
46.08 amu
What is the percentage composition of CuCl2?
47.27% Cu, 52.73% Cl
The percentage composition of sulfur in SO2 is about 50%. What is the percentage of oxygen in this compound?
50%
The mass of 1 mol of chromium (atomic mass 51.996 amu) is
51.996 g
The number of atoms in 1 mol of carbon is
6.022 * 10^23
The mass of 5.000 mol of cesium (atomic mass 132.9 amu) is
664.5 g
Bromine, atomic number 35, belongs to Group 17. How many electrons does bromine have in its outermost energy level?
7
The number of valence electrons in Group 17 elements is
7
The molar mass of CS2 is 76.15 g/mol. How many grams of CS2 are present in 10.00 mol?
761.5 g
Determine the mass in grams of 10.0 mol of bromine. The molar mass of bromine is 79.90 g/mol.
799 grams
In drawing a Lewis structure, each nonmetal atom except hydrogen should be surrounded by
8 electrons
Carbon-14 (atomic number 6), the radioactive nuclide used in dating fossils, has
8 neutrons
Determine the mass in grams of 5.00 mol of oxygen. The molar mass of oxygen is 16.00 g/mol
80 grams
What is the formula mass of magnesium chloride, MgCl2?
95.21 amu
Which of the following statements is true according to modern atomic theory?
Atoms of the same element may have different masses
Molar mass
Both a and b (is numerically equal to the average atomic mass of the element & is the mass in grams of one mole of a substance)
Which element has the following electron configuration: [Ar] 4s2 3d10 4p5?
Bromine
A compound's empirical formula is C2H5. If the formula mass is 58 amu, what is the molecular formula?
C4H10
What is the formula for the compound formed by calcium ions and chloride ions?
CaCl2
What element's orbital diagram is shown in the figure below?
Fluorine
What is the correct Lewis structure for hydrogen chloride, HCl?
H-Cl (with Cl with a full shell)
A compound contains 64 g of O and 8 g of H. What is the empirical formula for this compound?
H20
What is the empirical formula for a compound that is 31.9% potassium, 28.9% chlorine, and 39.2% oxygen?
KClO3
The idea of arranging the elements in the periodic table according to their chemical and physical properties is attributed to
Mendeleev
A compound's empirical formula is N2O5. If the formula mass is 108 amu, what is the molecular formula?
N2O5
What is the formula for sulfur dichloride?
SCl2
What is the empirical formula for a compound that is 53.3% O and 46.7% Si?
SiO2
Explain why metals are good conductors of electricity
They allow their electrons to move freely around, which helps them conduct electricity
What is the formula for zinc fluoride?
ZnF2
Write the noble-gas electron configuration represented in the orbital diagram below.
[Ne] 3s2 3p3
Write the noble-gas electron configuration for silicon.
[Ne] 3s23p2
The elements in Group 1 are also known as the
alkali metals
Name the compound Al2S3
aluminum sulfide
According to the quantum theory of an atom, in an orbital
an electron's position cannot be known precisely
A spherical electron cloud surrounding an atomic nucleus would best represent
an s orbital
A negative ion is known as a(n)
anion
In metals, the valence electrons
are shared by all of the atoms
Mendeleev noticed that properties of elements usually repeated at regular intervals when the elements were arranged in order of increasing
atomic mass
All atoms of the same element have the same
atomic number
Evidence gathered since Mendeleev's time indicates that a better arrangement than atomic mass for elements in the periodic table is an arrangement by
atomic number
The melting points of ionic compounds are higher than the melting points of molecular compounds because
attractive forces between ions are greater than the attractive forces between molecules
The atomic mass of an element listed in the periodic table is the
average atomic mass
Name the compound CF4
carbon tetrafluoride
A positive ion is known as a(n)
cation
After drawing a Lewis structure, one should
confirm that the total number of valence electrons used equals the number available
In a row in the periodic table, as the atomic number increases, the atomic radius generally
decreases
Name the compound N2O3
dinitrogen trioxide
In metallic bonds, the mobile electrons surrounding the positive ions are called a(n)
electron sea
What are shared in a covalent bond?
electrons
A formula that shows the simplest whole-number ratio of the atoms in a compound is the
empirical formula
The main energy level that can hold only two electrons is the
first
To find the molecular formula from the empirical formula, one must determine the compound's
formula mass
What is the sum of the atomic masses of all the atoms in a formula for a compound?
formula mass
If electrons in an atom have the lowest possible energies, the atom is in the
ground state
Refer to the figure below. To which group do fluorine and chlorine belong?
halogens
Hydrogen is placed separately from other elements in the periodic table because it
has many unique properties
Compared with ionic compounds, molecular compounds
have lower melting points
Ionic compounds are brittle because the strong attractive forces
hold the layers in relatively fixed positions
The B—F bond in BF3 (electronegativity for B is 2.0; electronegativity for F is 4.0) is
ionic
The empirical formula is always the accepted formula for a(n)
ionic compound
The energy required to remove an electron from an atom is the atom's
ionization energy
All of the following describe the Heisenberg uncertainly principle except
it helps to locate an electron in an atom
In drawing a Lewis structure, the central atom is generally the
least electronegative atom
Which of the following is NOT a property of an ionic compound?
low boiling point
The quantum number that indicates the position of an orbital about the three axes in space is the
magnetic quantum number
If a material can be shaped or extended by physical pressure, such as hammering, which property does the material have?
malleability
Atoms of the same element can differ in
mass number
The total number of protons and neutrons in the nucleus of an atom is its
mass number
Isotopes are atoms of the same element that have different
masses
The average atomic mass of an element
may not equal the mass of any of its isotopes
The molar mass of an element is the mass of one
mole of the element
Which of the following shows the types and numbers of atoms joined in a single molecule of a molecular compound?
molecular formula
The average atomic mass of an element is the average of the atomic masses of its
naturally occurring isotopes
A nuclear particle that has about the same mass as a proton, but with no electrical charge, is called a(n)
neutron
The discovery of what elements added a new column to Mendeleev's periodic table?
noble gases
If two covalently bonded atoms are identical, the bond is
nonpolar covalent
A chemical formula includes the symbols of the elements in the compound and subscripts that indicate
number of atoms or ions of each element that are combined in the compound
The periodic law states that the properties of elements are periodic functions of their atomic numbers. What determines the position of each element in the periodic table?
number of protons
All isotopes of hydrogen contain
one proton
A three-dimensional region around a nucleus where an electron may be found is called a(n)
orbital
Multiple covalent bonds may occur in atoms that contain carbon, nitrogen, or
oxygen
The electron configurations of the noble gases from neon to radon in the periodic table make these elements part of the
p block
The set of orbitals that are dumbbell shaped and directed along the x, y, and z axes are called
p orbitals
A horizontal row of blocks in the periodic table is called a(n)
period
The electron configuration of cesium, atomic number 55, is [Xe] 6s1. In what period is cesium?
period 6
If the atoms that share electrons have an unequal attraction for the electrons, the bond is called
polar
Elements in a group or column in the periodic table can be expected to have similar
properties
A positively charged particle with mass 1.673 ´ 10-24 g is a(n)
proton
The atomic number of oxygen, 8, indicates that there are eight
protons in the nucleus of an oxygen atom
The chemical formula for an ionic compound represents the
ratio of the combined ions present in a sample
The angular momentum quantum number indicates the
shape of an orbital
The empirical formula for a compound shows the symbols of the elements with subscripts indicating the
smallest whole-number ratio of the atoms
The properties of both ionic and molecular compounds are related to the
strengths of attraction between the particles in the compounds
An atom is electrically neutral because
the numbers of protons and electrons are equal
The correct Lewis structure for the oxygen atom has
two pairs of valence electrons and two single valence electrons
How many electrons can occupy the s orbitals at each energy level?
two, if they have opposite spins
Mendeleev predicted that the spaces in his periodic table represented
undiscovered elements
The electrons available to be lost, gained, or shared when atoms form compounds are called
valence electrons