Review Sample Questions
KHAN ACADEMY
Atoms, compounds, and ions | Chemistry | Science | Khan Academy
https://www.khanacademy.org/science/chemistry/atomic-structure-and-properties#names-and-formulas-of-ionic-compounds-quiz
Polyatomic ions (article) | Khan Academy
Naming ionic compound with polyvalent ion (video) | Khan Academy
Finding formula for ionic compounds (video) | Khan Academy
Find the formula for ionic compounds (practice) | Khan Academy
Naming ions and ionic compounds (video) | Khan Academy
Naming ionic compounds (practice) | Khan Academy
Chemical reactions introduction (video) | Khan Academy
Atoms, compounds, and ions | Chemistry | Science | Khan Academy
https://www.khanacademy.org/science/chemistry/atomic-structure-and-properties#names-and-formulas-of-ionic-compounds-quiz
Polyatomic ions (article) | Khan Academy
Naming ionic compound with polyvalent ion (video) | Khan Academy
Finding formula for ionic compounds (video) | Khan Academy
Find the formula for ionic compounds (practice) | Khan Academy
Naming ions and ionic compounds (video) | Khan Academy
Naming ionic compounds (practice) | Khan Academy
Chemical reactions introduction (video) | Khan Academy
1. States of the matter
2. Atomic structure
3. Electron configuration
Valence electrons, octet rule
4. Periodic table of elements
5. Ions and ionic bond and ionic compounds
Writing formulas of ionic compound or naming them when the formula is given
6. Covalent bonds
7. Chemical reactions
Chemical vs physical change
Types of reactions
Chemical equations
SAMPLE QUESTIONS
The state of matter in which a material has definite shape and definite
volume is the state.
a. liquid
b. solid
c. gaseous
d. vaporous
The state of matter in which a material has a definite volume but no
definite shape is the state.
a. gaseous
b. liquid
c. elemental
d. solid
The particles in a solid are
a. packed closely together.
b. very far apart.
c. free to move independently.
d. able to slide past each other.
The melting of candle wax is classified as a physical change because it
a. produces no new substances.
b. transfers energy.
c. absorbs energy.
d. changes the chemical properties of wax.
A physical change is observed when
a. ice melts.
b. milk sours.
c. silver tarnishes.
d. wood burns.
An example of a chemical change is
a. sanding wood.
b. melting iron.
c. baking bread.
d. vaporizing gasoline.
Matter that is free to move and fills its available volume is in the
state.
a. liquid
b. solid
c. gaseous
d. elemental
The state of matter in which a material is most likely to resist
compression is the
a. solid state.
b. liquid state.
c. gaseous state.
d. vaporous state.
A chemical change occurs when
a. dissolved minerals solidify to form a crystal.
b. ethanol is purified through distillation.
c. salt deposits form from evaporated seawater.
d. a leaf changes color.
Which of the following shows a physical change occurring?
a. A peach spoils.
b. A copper bowl tarnishes.
c. A piece of jewelry turns your skin green.
d. A hot-glue gun melts a glue stick.
Which of the following observations does not indicate that a chemical
change has occurred?
a. change of state
b. formation of a precipitate
c. absorption of energy
d. release of a gas
One chemical property of matter is
a. boiling point.
b. texture.
c. reactivity.
d. density.
Which of the following mixtures is homogeneous?
a. iced tea
b. a cheeseburger
c. pizza
d. vegetable soup
What type of matter is formed when two or more elements chemically
join together?
a. compound
b. element
c. heterogeneous mixture
d. homogeneous mixture
The abbreviations for units of length in order from smallest to largest
are
a. m, cm, mm, km.
b. mm, m, cm, km.
c. km, mm, cm, m.
d. mm, cm, m, km.
SI standard units for length and mass are
a. centimeter and gram.
b. meter and gram.
c. centimeter and kilogram.
d. meter and kilogram.
Which statement is not true?
a. Some elements exist as molecules.
b. Some elements exist as atoms.
c. Molecules are composed only of a single type of atom.
d. All molecules of a given substance are the same.
The law that states that mass cannot be created or destroyed in
ordinary chemical and physical changes is known as the law of
a. conservation of mass.
b. mass action.
c. multiple proportions.
d. definite composition.
The observation that the mass of carbon dioxide formed from the
reaction of carbon and oxygen equals the combined masses of the
carbon and oxygen that reacted supports the law of
a. conservation of mass.
b. mass action.
c. multiple proportions.
d. definite composition.
The behavior of cathode rays led scientists to conclude that the rays
were composed of
a. energy.
b. positively charged particles.
c. negatively charged particles.
d. uncharged particles.
Because cathodes made of different metallic elements produced
cathode rays, scientists generalized that
a. all atoms have electrons.
b. atoms are indivisible.
c. atoms carry a positive charge.
d. electrons vary in charge.
Because most of the alpha particles in Rutherford’s gold-foil
experiments passed through the foil, he concluded that
a. atoms were mostly empty space.
b. atoms contained no charged particles.
c. electrons formed the nucleus.
d. atoms are indivisible.
According to the Bohr model of the atom, which particles are allowed
to exist in any one of a number of energy levels.
a. electrons
b. protons
c. neutrons
d. Both (b) and (c)
Which of the following atomic models is also referred to as the
“electron-cloud” model of the atom?
a. Thompson’s plum pudding model
b. Rutherford model
c. Bohr model
d. quantum model
The line-emission spectrum of an atom is caused by the energies
released when electrons
a. jump from a lower energy level to a higher energy level.
b. jump from a higher energy level to a lower energy level.
c. jump from the ground state to an excited state.
d. None of the above
Because excited hydrogen atoms always produced the same lineemission
spectrum, scientists concluded that hydrogen
a. had no electrons.
b. did not release energy.
c. released energy of only certain values.
d. could only exist in the ground state.
The electron configuration of 27
13Al is
a. 1s22s22p63s13d2.
b. 1s22s22p53s23p2.
c. [Ne] 3s23p1.
d. [Ne] 3s13p13d1.
Atoms contain equal numbers of
a. electrons and neutrons.
b. protons and neutrons.
c. protons and electrons.
d. protons, electrons, and neutrons.
The atomic symbol for beryllium, 9,4
Be, indicates that the
a. atomic number is 4.
b. atomic number is 9.
c. mass number is 4.
d. atomic number is equal to 9 4.
An atom of potassium has 19 protons and 20 neutrons. Its mass number
is
a. 9.
b. 19.
c. 20.
d. 39.
The atomic mass unit is used to express
a. atomic mass.
b. atomic mass number.
c. atomic number.
d. molar mass.
Using a periodic table, find the identity of the element that has an
atomic mass of 40.078 amu.
a. C
b. Ca
c. Cr
d. Cu
In developing his periodic table, Mendeleev listed on cards each element’s
name, atomic mass, and
a. atomic number.
b. electron configuration.
c. isotopes.
d. properties.
Mendeleev’s periodic table did not always list elements in order of increasing atomic mass because he grouped together elements with similar
a. properties.
b. atomic numbers.
c. densities.
d. colors.
Mendeleev attempted to organize the chemical elements based on their
a. symbols.
b. properties.
c. atomic numbers.
d. electron configurations.
Mendeleev predicted that the gaps in his periodic table represented
a. isotopes.
b. radioactive elements.
c. permanent gaps.
d. undiscovered elements.
An electron that is found in the outermost shell of an atom and determines
the atom’s chemical properties is called a(n)
a. valence electron.
b. paired electron.
c. p electron.
d. octave electron.
A horizontal row in the periodic table is called a(n)
a. family.
b. group.
c. octet.
d. period.
The periodic law states that the physical and chemical properties of
elements are periodic functions of their atomic
a. masses.
b. numbers.
c. radii.
d. structures.
A horizontal row in the periodic table is called a(n)
a. family.
b. group.
c. octet.
d. period.
Refer to a periodic table. In which period is calcium?
a. Period 2
b. Period 4
c. Period 6
d. Period 8
Refer to a periodic table. In which group is calcium?
a. Group 1
b. Group 2
c. Group 17
d. Group 18
An element that has the electron configuration [Ne]3s23p5 is in which
period?
a. Period 2
b. Period 3
c. Period 5
d. Period 7
An element that has the electron configuration [Ne]3s23p5 is in which
group?
a. Group 2
b. Group 5
c. Group 7
d. Group 17
Elements in the s- or p-blocks of the periodic table are called
a. alloys.
b. main-group elements.
c. metals.
d. transition metals.
Elements in Group 18 have
a. very low reactivity.
b. good conductivity.
c. very high reactivity.
d. metallic character.
Nonmetallic elements in Group 17 that react with metals to form salts
are
a. alkali-metals.
b. halogens.
c. lanthanides.
d. noble gases.
The alkali metals are found on Earth only in compounds because they
a. have small atoms.
b. are very reactive elements.
c. are rare elements.
d. are metallic elements.
An element with the lowest electronegativity would be found in
of the periodic table.
a. Group 1, Period 7
b. Group 3, Period 4
c. Group 5, Period 3
d. Group 17, Period 2
Refer to a periodic table and determine which element has the lowest
electron affinity.
a. Cl
b. Se
c. Cs
d. Te
Which of the following elements has the lowest electronegativity?
a. C
b. F
c. Li
d. O
Which of the following elements behaves similarly to calcium?
a. magnesium
b. sodium
c. sulfur
d. chlorine
Which of the following electron configurations belong to an element
that is the most chemically reactive?
a. 1s2
b. 1s22s22p6
c. 1s22s22p5
d. 1s22s22p63s23p6
An octet is equal to
a. 2.
b. 4.
c. 5.
d. 8.
Which of the following situations will cause the element with the electron
configuration 1s22s22p5 to have an octet configuration?
a. loss of one electron
b. gain of one electron
c. loss of two electrons
d. gain of three electrons
The elements of Group are able to satisfy the octet rule without
forming compounds.
a. 1
b. 2
c. 17
d. 18
An element with the electron configuration 1s22s22p63s23p64s2 will
ionize to a(n)
a. anion.
b. cation.
c. noble gas.
d. Both (a) and (b)
An element with the electron configuration 1s22s22p63s23p5 will ionize
to a(n)
a. anion.
b. cation.
c. noble gas.
d. Both (a) and (b)
An ion and its parent atom differ in
a. electron configuration.
b. number of electrons.
c. chemical reactivity.
d. All of the above
The electrostatic attraction between _____ forms an ionic bond.
a. dipoles
b. electrons
c. ions
d. nuclei
The salts NaCl(solid) and CaCl2(solid)
a. are good conductors of electricity.
b. are positively charged.
c. are held together by ionic bonds.
d. Both (a) and (b)
A compound that vaporizes readily at room temperature is most likely
to be a(n)
a. dipolar compound.
b. ionic compound.
c. metal.
d. molecular compound.
Compared with solid ionic compounds, solid molecular compounds
a. have lower melting points.
b. are more brittle.
c. are harder.
d. conduct electricity as liquids.
Compounds that have the same number of positive and negative
charges are said to be
a. cationic.
b. anionic.
c. electrically neutral.
d. isoelectronic.
An ion of bromine with a single negative charge has the symbol and
the name
a. Br+, bromide ion.
b. Br-, bromide ion.
c. Br+, bromium ion.
d. Br-, bromium ion.
What is the formula for the compound formed by aluminum, Al3, and
the sulfate ion, SO24
?
a. AlSO4
b. Al3SO4
c. Al2(SO4)3
d. Al(SO4)3
The charge on an ion is
a. always positive.
b. always negative.
c. either positive or negative.
d. zero.
The pair of ions listed below with similar chemical properties is
a. F- and Cl-.
b. F-and Li+.
c. Na+ and Cl-.
d. Na+ and F-.
The correct name for the salt with the formula CaI2 is
a. calcium diodide.
b. calcium iodine.
c. calcium iodide.
d. dicalcium iodine.
The correct formula for magnesium oxide is
a. Mg2O.
b. MgO.
c. MgO2.
d. Mg2O3.
The correct name for the compound with the formula CaSO4 is
a. calcium sulfur oxide.
b. calcium sulfide.
c. calcium sulfate.
d. calcium sulfur tetroxide.
Ionic bonding always takes place between
a. ions of opposite electrical charge.
b. ions of the same electrical charge.
c. ions of the same size.
d. ions of the same size and opposite charge.
Ionic compounds conduct electricity except when they are
a. in water solution.
b. liquid.
c. binary compounds.
d. solid.
An element with which of the following electron configurations is NOT
chemically reactive?
a. 1s22s22p4
b. 1s22s22p63s23p5
c. 1s22s22p63s23p6
d. 1s22s22p63s23p64s1
The melting points of ionic compounds are higher than the melting
points of molecular compounds because
a. ionic substances tend to vaporize at room temperature.
b. ionic substances are brittle.
c. attractive forces between ions are greater than the attractive forces
between molecules.
d. None of the above
A covalent bond is formed when two atoms
a. share an electron with each other.
b. share one or more pairs of electrons with each other.
c. gain electrons.
d. gain and lose electrons.
A single covalent bond involves the sharing of
a. only one electron.
b. two electrons.
c. three electrons.
d. a variable number of electrons, which depends on the bonding atoms.
Which statement is true about a molecule of H2?
a. Each atom has an electron configuration like that of helium.
b. It is less stable than either of the hydrogen atoms by itself.
c. The electrons from both atoms travel within the molecular orbital.
d. Both (a) and (c)
The electrons involved in the formation of a covalent bond are
a. transferred from one atom to another.
b. found only in the s-orbitals.
c. valence electrons.
d. in filled orbitals.
The atom with the highest electronegativity among those listed below
is likely to be
a. H.
b. Na.
c. C.
d. Cl.
The less the electronegativity difference between two bonded atoms
is, the greater the of the bond.
a. covalent character
b. ionic character
c. metallic character
d. Both (b) and (c)
A Lewis structure does not show
a. valence electrons.
b. bond energies.
c. bonds.
d. atoms.
The correct name for the compound P2O5 is
a. phosphorus oxide.
b. diphosphorus oxide.
c. phosphorus pentoxide.
d. diphosphorus pentoxide.
The correct chemical formula for tetraphosphorus decaoxide is
a. P1O2.
b. P2O1.
c. P3O3.
d. P4O10.
As atoms bond with each other, they
a. increase their potential energy, thus creating less-stable arrangements
of matter.
b. decrease their potential energy, thus creating less-stable arrangements
of matter.
c. increase their potential energy, thus creating more-stable arrangements
of matter.
d. decrease their potential energy, thus creating more-stable arrangements
of matter.
In which of these compounds is the bond between the atoms not a
nonpolar covalent bond?
a. Cl2
b. H2
c. HCl
d. O2
A polar covalent bond forms between A and B when
a. the electronegativity difference is zero.
b. the molecular orbital is found nearer one atom.
c. the bond produces two ions.
d. the bond is increased by the shape of the molecule.
Drawing Lewis Structures with Many Atoms
The state of matter in which a material has definite shape and definite
volume is the state.
a. liquid
b. solid
c. gaseous
d. vaporous
The state of matter in which a material has a definite volume but no
definite shape is the state.
a. gaseous
b. liquid
c. elemental
d. solid
The particles in a solid are
a. packed closely together.
b. very far apart.
c. free to move independently.
d. able to slide past each other.
The melting of candle wax is classified as a physical change because it
a. produces no new substances.
b. transfers energy.
c. absorbs energy.
d. changes the chemical properties of wax.
A physical change is observed when
a. ice melts.
b. milk sours.
c. silver tarnishes.
d. wood burns.
An example of a chemical change is
a. sanding wood.
b. melting iron.
c. baking bread.
d. vaporizing gasoline.
Matter that is free to move and fills its available volume is in the
state.
a. liquid
b. solid
c. gaseous
d. elemental
The state of matter in which a material is most likely to resist
compression is the
a. solid state.
b. liquid state.
c. gaseous state.
d. vaporous state.
A chemical change occurs when
a. dissolved minerals solidify to form a crystal.
b. ethanol is purified through distillation.
c. salt deposits form from evaporated seawater.
d. a leaf changes color.
Which of the following shows a physical change occurring?
a. A peach spoils.
b. A copper bowl tarnishes.
c. A piece of jewelry turns your skin green.
d. A hot-glue gun melts a glue stick.
Which of the following observations does not indicate that a chemical
change has occurred?
a. change of state
b. formation of a precipitate
c. absorption of energy
d. release of a gas
One chemical property of matter is
a. boiling point.
b. texture.
c. reactivity.
d. density.
Which of the following mixtures is homogeneous?
a. iced tea
b. a cheeseburger
c. pizza
d. vegetable soup
What type of matter is formed when two or more elements chemically
join together?
a. compound
b. element
c. heterogeneous mixture
d. homogeneous mixture
The abbreviations for units of length in order from smallest to largest
are
a. m, cm, mm, km.
b. mm, m, cm, km.
c. km, mm, cm, m.
d. mm, cm, m, km.
SI standard units for length and mass are
a. centimeter and gram.
b. meter and gram.
c. centimeter and kilogram.
d. meter and kilogram.
Which statement is not true?
a. Some elements exist as molecules.
b. Some elements exist as atoms.
c. Molecules are composed only of a single type of atom.
d. All molecules of a given substance are the same.
The law that states that mass cannot be created or destroyed in
ordinary chemical and physical changes is known as the law of
a. conservation of mass.
b. mass action.
c. multiple proportions.
d. definite composition.
The observation that the mass of carbon dioxide formed from the
reaction of carbon and oxygen equals the combined masses of the
carbon and oxygen that reacted supports the law of
a. conservation of mass.
b. mass action.
c. multiple proportions.
d. definite composition.
The behavior of cathode rays led scientists to conclude that the rays
were composed of
a. energy.
b. positively charged particles.
c. negatively charged particles.
d. uncharged particles.
Because cathodes made of different metallic elements produced
cathode rays, scientists generalized that
a. all atoms have electrons.
b. atoms are indivisible.
c. atoms carry a positive charge.
d. electrons vary in charge.
Because most of the alpha particles in Rutherford’s gold-foil
experiments passed through the foil, he concluded that
a. atoms were mostly empty space.
b. atoms contained no charged particles.
c. electrons formed the nucleus.
d. atoms are indivisible.
According to the Bohr model of the atom, which particles are allowed
to exist in any one of a number of energy levels.
a. electrons
b. protons
c. neutrons
d. Both (b) and (c)
Which of the following atomic models is also referred to as the
“electron-cloud” model of the atom?
a. Thompson’s plum pudding model
b. Rutherford model
c. Bohr model
d. quantum model
The line-emission spectrum of an atom is caused by the energies
released when electrons
a. jump from a lower energy level to a higher energy level.
b. jump from a higher energy level to a lower energy level.
c. jump from the ground state to an excited state.
d. None of the above
Because excited hydrogen atoms always produced the same lineemission
spectrum, scientists concluded that hydrogen
a. had no electrons.
b. did not release energy.
c. released energy of only certain values.
d. could only exist in the ground state.
The electron configuration of 27
13Al is
a. 1s22s22p63s13d2.
b. 1s22s22p53s23p2.
c. [Ne] 3s23p1.
d. [Ne] 3s13p13d1.
Atoms contain equal numbers of
a. electrons and neutrons.
b. protons and neutrons.
c. protons and electrons.
d. protons, electrons, and neutrons.
The atomic symbol for beryllium, 9,4
Be, indicates that the
a. atomic number is 4.
b. atomic number is 9.
c. mass number is 4.
d. atomic number is equal to 9 4.
An atom of potassium has 19 protons and 20 neutrons. Its mass number
is
a. 9.
b. 19.
c. 20.
d. 39.
The atomic mass unit is used to express
a. atomic mass.
b. atomic mass number.
c. atomic number.
d. molar mass.
Using a periodic table, find the identity of the element that has an
atomic mass of 40.078 amu.
a. C
b. Ca
c. Cr
d. Cu
In developing his periodic table, Mendeleev listed on cards each element’s
name, atomic mass, and
a. atomic number.
b. electron configuration.
c. isotopes.
d. properties.
Mendeleev’s periodic table did not always list elements in order of increasing atomic mass because he grouped together elements with similar
a. properties.
b. atomic numbers.
c. densities.
d. colors.
Mendeleev attempted to organize the chemical elements based on their
a. symbols.
b. properties.
c. atomic numbers.
d. electron configurations.
Mendeleev predicted that the gaps in his periodic table represented
a. isotopes.
b. radioactive elements.
c. permanent gaps.
d. undiscovered elements.
An electron that is found in the outermost shell of an atom and determines
the atom’s chemical properties is called a(n)
a. valence electron.
b. paired electron.
c. p electron.
d. octave electron.
A horizontal row in the periodic table is called a(n)
a. family.
b. group.
c. octet.
d. period.
The periodic law states that the physical and chemical properties of
elements are periodic functions of their atomic
a. masses.
b. numbers.
c. radii.
d. structures.
A horizontal row in the periodic table is called a(n)
a. family.
b. group.
c. octet.
d. period.
Refer to a periodic table. In which period is calcium?
a. Period 2
b. Period 4
c. Period 6
d. Period 8
Refer to a periodic table. In which group is calcium?
a. Group 1
b. Group 2
c. Group 17
d. Group 18
An element that has the electron configuration [Ne]3s23p5 is in which
period?
a. Period 2
b. Period 3
c. Period 5
d. Period 7
An element that has the electron configuration [Ne]3s23p5 is in which
group?
a. Group 2
b. Group 5
c. Group 7
d. Group 17
Elements in the s- or p-blocks of the periodic table are called
a. alloys.
b. main-group elements.
c. metals.
d. transition metals.
Elements in Group 18 have
a. very low reactivity.
b. good conductivity.
c. very high reactivity.
d. metallic character.
Nonmetallic elements in Group 17 that react with metals to form salts
are
a. alkali-metals.
b. halogens.
c. lanthanides.
d. noble gases.
The alkali metals are found on Earth only in compounds because they
a. have small atoms.
b. are very reactive elements.
c. are rare elements.
d. are metallic elements.
An element with the lowest electronegativity would be found in
of the periodic table.
a. Group 1, Period 7
b. Group 3, Period 4
c. Group 5, Period 3
d. Group 17, Period 2
Refer to a periodic table and determine which element has the lowest
electron affinity.
a. Cl
b. Se
c. Cs
d. Te
Which of the following elements has the lowest electronegativity?
a. C
b. F
c. Li
d. O
Which of the following elements behaves similarly to calcium?
a. magnesium
b. sodium
c. sulfur
d. chlorine
Which of the following electron configurations belong to an element
that is the most chemically reactive?
a. 1s2
b. 1s22s22p6
c. 1s22s22p5
d. 1s22s22p63s23p6
An octet is equal to
a. 2.
b. 4.
c. 5.
d. 8.
Which of the following situations will cause the element with the electron
configuration 1s22s22p5 to have an octet configuration?
a. loss of one electron
b. gain of one electron
c. loss of two electrons
d. gain of three electrons
The elements of Group are able to satisfy the octet rule without
forming compounds.
a. 1
b. 2
c. 17
d. 18
An element with the electron configuration 1s22s22p63s23p64s2 will
ionize to a(n)
a. anion.
b. cation.
c. noble gas.
d. Both (a) and (b)
An element with the electron configuration 1s22s22p63s23p5 will ionize
to a(n)
a. anion.
b. cation.
c. noble gas.
d. Both (a) and (b)
An ion and its parent atom differ in
a. electron configuration.
b. number of electrons.
c. chemical reactivity.
d. All of the above
The electrostatic attraction between _____ forms an ionic bond.
a. dipoles
b. electrons
c. ions
d. nuclei
The salts NaCl(solid) and CaCl2(solid)
a. are good conductors of electricity.
b. are positively charged.
c. are held together by ionic bonds.
d. Both (a) and (b)
A compound that vaporizes readily at room temperature is most likely
to be a(n)
a. dipolar compound.
b. ionic compound.
c. metal.
d. molecular compound.
Compared with solid ionic compounds, solid molecular compounds
a. have lower melting points.
b. are more brittle.
c. are harder.
d. conduct electricity as liquids.
Compounds that have the same number of positive and negative
charges are said to be
a. cationic.
b. anionic.
c. electrically neutral.
d. isoelectronic.
An ion of bromine with a single negative charge has the symbol and
the name
a. Br+, bromide ion.
b. Br-, bromide ion.
c. Br+, bromium ion.
d. Br-, bromium ion.
What is the formula for the compound formed by aluminum, Al3, and
the sulfate ion, SO24
?
a. AlSO4
b. Al3SO4
c. Al2(SO4)3
d. Al(SO4)3
The charge on an ion is
a. always positive.
b. always negative.
c. either positive or negative.
d. zero.
The pair of ions listed below with similar chemical properties is
a. F- and Cl-.
b. F-and Li+.
c. Na+ and Cl-.
d. Na+ and F-.
The correct name for the salt with the formula CaI2 is
a. calcium diodide.
b. calcium iodine.
c. calcium iodide.
d. dicalcium iodine.
The correct formula for magnesium oxide is
a. Mg2O.
b. MgO.
c. MgO2.
d. Mg2O3.
The correct name for the compound with the formula CaSO4 is
a. calcium sulfur oxide.
b. calcium sulfide.
c. calcium sulfate.
d. calcium sulfur tetroxide.
Ionic bonding always takes place between
a. ions of opposite electrical charge.
b. ions of the same electrical charge.
c. ions of the same size.
d. ions of the same size and opposite charge.
Ionic compounds conduct electricity except when they are
a. in water solution.
b. liquid.
c. binary compounds.
d. solid.
An element with which of the following electron configurations is NOT
chemically reactive?
a. 1s22s22p4
b. 1s22s22p63s23p5
c. 1s22s22p63s23p6
d. 1s22s22p63s23p64s1
The melting points of ionic compounds are higher than the melting
points of molecular compounds because
a. ionic substances tend to vaporize at room temperature.
b. ionic substances are brittle.
c. attractive forces between ions are greater than the attractive forces
between molecules.
d. None of the above
A covalent bond is formed when two atoms
a. share an electron with each other.
b. share one or more pairs of electrons with each other.
c. gain electrons.
d. gain and lose electrons.
A single covalent bond involves the sharing of
a. only one electron.
b. two electrons.
c. three electrons.
d. a variable number of electrons, which depends on the bonding atoms.
Which statement is true about a molecule of H2?
a. Each atom has an electron configuration like that of helium.
b. It is less stable than either of the hydrogen atoms by itself.
c. The electrons from both atoms travel within the molecular orbital.
d. Both (a) and (c)
The electrons involved in the formation of a covalent bond are
a. transferred from one atom to another.
b. found only in the s-orbitals.
c. valence electrons.
d. in filled orbitals.
The atom with the highest electronegativity among those listed below
is likely to be
a. H.
b. Na.
c. C.
d. Cl.
The less the electronegativity difference between two bonded atoms
is, the greater the of the bond.
a. covalent character
b. ionic character
c. metallic character
d. Both (b) and (c)
A Lewis structure does not show
a. valence electrons.
b. bond energies.
c. bonds.
d. atoms.
The correct name for the compound P2O5 is
a. phosphorus oxide.
b. diphosphorus oxide.
c. phosphorus pentoxide.
d. diphosphorus pentoxide.
The correct chemical formula for tetraphosphorus decaoxide is
a. P1O2.
b. P2O1.
c. P3O3.
d. P4O10.
As atoms bond with each other, they
a. increase their potential energy, thus creating less-stable arrangements
of matter.
b. decrease their potential energy, thus creating less-stable arrangements
of matter.
c. increase their potential energy, thus creating more-stable arrangements
of matter.
d. decrease their potential energy, thus creating more-stable arrangements
of matter.
In which of these compounds is the bond between the atoms not a
nonpolar covalent bond?
a. Cl2
b. H2
c. HCl
d. O2
A polar covalent bond forms between A and B when
a. the electronegativity difference is zero.
b. the molecular orbital is found nearer one atom.
c. the bond produces two ions.
d. the bond is increased by the shape of the molecule.
Drawing Lewis Structures with Many Atoms