The Chemical Context of Life

The atomic number of neon is 10. Therefore it

1. has 8 electrons in the outer electron shell.
2. is inert.
3. has an atomic mass of 10.
1. 1
2. 2
3. 3
4. 1 and 2 are correct
5. 1, 2, and 3 are correct
An atomic form of an element containing different numbers of neutrons is _________.
1. an isotope
2. an ion
3. a polar atom
4. an isomer
5. radioactive
Oxygen has an atomic number of 8. Therefore, it must have

1. 8 protons
2. 8 electrons
3. 8 neutrons
1. 1
2. 2
3. 3
4. 1 and 2 are correct
5. 1, 2, and 3 are correct
What are the chemical properties of atoms whose valence shells are filled?
1. They form ionic bonds in aqueous solutions.
2. They form covalent bonds in aqueous solutions.
3. They are particularly stable and unreactive
4. They exhibit similar chemical behaviors.
Each element is unique and different from other elements because of its

1. atomic weight
2. atomic number
3. mass number
1. 1
2. 2
3. 3
4. 1 and 2 are correct
5. 1, 2, and 3 are correct
What do atoms form when they share electron pairs?
1. elements
2. ions
3. aggregates
4. isotopes
5. molecules
Results from a transfer of electron(s) between atoms

1. nonpolar covalent bond
2. polar covalent bond
3. ionic bond
4. hydrogen bond
5. hydrophobic interaction
1. 1
2. 2
3. 3
4. 4
5. 5
Results from an unequal sharing of electrons between atoms creates

1. nonpolar covalent bond
2. polar covalent bond
3. ionic bond
4. hydrogen bond
5. hydrophobic interaction
1. 1
2. 2
3. 3
4. 4
5. 5
Which of the following explains most specifically the attraction of water molecules to each other.

1. nonpolar covalent bond
2. polar covalent bond
3. ionic bond
4. hydrogen bond
5. hydrophobic interaction
1. 1
2. 2
3. 3
4. 4
5. 5
Which of the following would be least affected by the presence of water?

1. nonpolar covalent bond
2. polar covalent bond
3. ionic bond
4. hydrogen bond
5. hydrophobic interaction
1. 1
2. 2
3. 3
4. 4
5. 5
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following statements is CORRECT about ammonia (NH₃)?
1. Each hydrogen atom has a partial positive charge.
2. The nitrogen atom has a strong positive charge.
3. Each hydrogen atom has a slight negative charge.
4. The nitrogen atom has a partial positive charge.
5. There are covalent bonds between the hydrogen atoms.
What is the maximum number of covalent bonds an element with atomic number 16 can make with hydrogen?
1. 1
2. 2
3. 3
4. 4
5. 5
One difference between carbon 12 and carbon 14 is that carbon 14 has

1. 2 more protons than carbon 12.
2. 2 more electrons than carbon 12.
3. 2 more neutrons than carbon 12.
1. 1
2. 2
3. 3
4. 1 and 3 are correct
5. 1, 2, and 3 are correct
When two atoms are equally electronegative, they will interact to form
1. equal numbers of isotopes.
2. ions.
3. polar covalent bonds.
4. nonpolar covalent bonds.
5. ionic bonds.
How do isotopes differ from each other?
1. number of protons
2. number of electrons
3. number of neutrons
4. valence electron distribution
5. ability to form ions
The reactive properties of an atom depend on the number of
1. valence shells in the atom.
2. orbitals found in the atom.
3. electrons n each orbital in the atom.
4. electrons in the outer valence shell in the atom.
5. hydridized orbitals in the atom.
The mass number of an element can be easily approximated by adding together the number of
1. protons and neutrons.
2. electron orbitals in each energy level.
3. protons and electrons.
4. neutrons and electrons.
5. isotopes of the atom.
Atoms whose outer electorn shells contain eight electrons tend to
1. form ionic bonds in aqueous solutions.
2. form covalent bonds in aqueous solutions.
3. be particularly stable and nonreactive.
4. be particularly unstable and very reactive.
5. be biologically important since they are present in organic molecules.
Use the table below to answer the following question.

How many electrons does carbon have in its outermost (valence) energy level?
1. 4
2. 8
3. 7
4. 5
5. 2
Use the table below to answer the following question.

How many neutrons does the nucleus of sulfur contain?
1. 16
2. 19
3. 32
4. 35
5. 51
Use the table below to answer the following question.

Based on electron configuration, which of these elements would exhibit chemical behavior most like that of oxygen?

Based on electon configuration, which of these elements would exhibit chemical behavior most
1. C
2. H
3. N
4. S
5. P
The atomic number of each atom is given to the left of each of the elements below. Which of the atoms has the same valence as carbon?
1. 7 nitrogen
2. 9 fluorine
3. 10 neon
4. 12 magnesium
5. 14 silicon
Which of the following is a trace element that is essential to humans?
1. Nitrogen
2. Calcium
3. Iodine
4. Carbon
5. Oxygen
Which of the following represents a polar covalent bond?
1. H--H
2. C--C
3. H--O
4. C--H
5. O--O
A covalent bond is likely to be polar when
1. one of the atoms sharing electrons is much more electronegative than the other atom.
2. the two atoms sharing electrons are equally electronegative.
3. the two atoms sharing electrons are the same element.
4. it is between two atoms that are both very strong electron acceptors.
5. the two atoms sharing electrons are different elements.
What bond(s) is (are) easily disrupted in the presence of water?

1. covalent
2. polar covalent
3. ionic
1. 1
2. 2
3. 3
4. 1 and 2 are correct
5. 1, 2, and 3 are correct
From its atomic number of 15, it is possible to predict that the phosphorus atom has

1. 15 neutrons
2. 15 protons
3. 15 electrons
1. 1
2. 2
3. 3
4. 1 and 2 are correct
5. 1, 2 and 3 are correct
The ionic bond of sodium chloride is formed when
1. chlorine gains an electron from sodium.
2. sodium and chlorine share an electron pair.
3. sodium and chlorine both lose electrons from their outer energy levels.
4. sodium gains an electron from chlorine.
5. chlorine gains a proton from sodium
Which of the following best describes the relationship between the atoms listed below?
1. They are isomers.
2. They are polymers.
3. They are isotopes.
4. They are ions.
5. They are both radioactive.
How many electrons would be expected in the outer energy level of an atom with an atomic number 17?
1. 2
2. 5
3. 7
4. 8
5. 17
The atomic number of carbon is 6. 14C is heavier than 12C because 14C has
1. six protons.
2. six neutrons.
3. eight protons.
4. eight neutrons.
5. fourteen electrons.
Use the Figure below to answer the question.

Which of the drawings depicts the electron configuration of neon?
1. A
2. B
3. C
4. D
5. E
Use the Figure below to answer the question.

Which of the drawings depicts the electron configuration of oxygen?
1. A
2. B
3. C
4. D
5. E
Use the Figure below to answer the question.

Which of the drawings depicts the electron configuration of carbon?
1. A
2. B
3. C
4. D
5. E
Use the Figure below to answer the question.

Which of the drawings is of an atom with the atomic number of eight?
1. A
2. B
3. C
4. D
5. E
Use the Figure below to answer the question.

Which of the drawings depicts an atom that is inert?
1. A
2. B
3. C
4. D
5. E
Use the Figure below to answer the question.

Which of the drawings depicts an atom with a valence of three?
1. A
2. B
3. C
4. D
5. E
The number of electrons carbon shares with the oxygens in a molecule of CO2 is
1. 1
2. 2
3. 3
4. 4
5. 5
The number of additional electrons needed to complete the valence shell of hydrogen is
1. 1
2. 2
3. 3
4. 4
5. 5
The valence of an atom with 7 electrons in its outer electron shell is
1. 1
2. 2
3. 3
4. 4
5. 5
The number of protons in an atom with the atomic number of 5 is
1. 1
2. 2
3. 3
4. 4
5. 5
The maximum number of electrons in the first orbital of an atom is
1. 1
2. 2
3. 3
4. 4
5. 5
Which four elements make up approximately 96% of living matter?
1. carbon, hydrogen, nitrogen, oxygen
2. carbon, sulfur, phosphorus, hydrogen
3. oxygen, hydrogen, calcium, sodium
4. carbon, sodium, chlorine, magnesium
5. carbon, oxygen, sulfur, calcium
What results from the chemical reaction illustrated in the Figure below
1. isotopes
2. ions
3. a covalent bond
4. a hydrogen bond
5. hydrophobic interactions
A covalent chemical bond is one in which
1. electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged.
2. protons or neutrons are shared by two atoms so as to satisfy the requirements of both.
3. outer shell electrons are shared by two atoms so as to satisfactorily fill the outer electron shells of both.
4. outer shell elecvtrons of one atom are transferred to the inner electron shells of another atom.
5. the inner shell electrons of one atom are transferred to th eouter shell of another atom.
Use the table below to answer the question.

If an atom ( X ) with an atomic number 6 were allowed to react with hydrogen, the molecule formed would be
1. A
2. B
3. C
4. D
5. E
What do the four elements most abundant in life -- carbon, oxygen, hydrogen, and nitrogen -- have in common?
1. They all have the same number of valence electrons.
2. Each element exists in only one isotopic form.
3. They are equal in electronegativity.
4. They are elements produced only by living cells.
5. They all have unpaired electrons in their valence shells.
Which type of bond is important in large biological molecules?

1. Covalent
2. Hydrogen
3. Ionic
4. Polar covalent
1. 1
2. 2
3. 3
4. 4
5. All the bonds are important.
Which of the following best explains the distinction between biology and chemistry?
1. Biologists study living things while chemists study nonliving things.
2. Biology has a hierarchy of structural levels, while chemistry does not.
3. Chemists study molecules, while biologists do not.
4. Biological systems have emergent properties; chemical systems do not.
5. There is no clear distinction because the two sciences are parts of the same whole.
Which of the following best describes chemical equilibrium?
1. reactions continuing with no effect on the concentrations of reactants and products.
2. concentrations of products are high.
3. reactions have stopped.
4. reactions stop only when all of the reactants have been converted to products.
5. equal concentrations of reactants and products.
What bond does NH₄ form with Cl to make ammonium chloride salt?
1. nonpolar covalent bond
2. polar covalent bond
3. ionic bond
4. hydrogen bond
5. non of these answers is correct.
What is the formula for ammonium chloride salt?
1. NHCl
2. NH₄Cl
3. NH₄Cl₂
4. NHCl₂
5. ClNH
Which atom is the cation in ammonium chloride salt?
1. NH₄
2. Cl
3. H
4. N
The shape of a molecule
1. determines its biological function.
2. is determined by orbital positions of its atoms.
3. determines how molecules recognize and respond to each other.
4. may aid in the formation of bonds.
5. All answers are correct.
Which of the following is TRUE for the reaction depicted below?

3H₃ + N₂ <---> 2NH₃
1. The reaction is nonreversible.
2. Ammonia is being formed.
3. Concentrations of reactants are higher than those of products.
4. Ammonia is being formed and decomposed.
5. Hydrogen and nitrogen are being decomposed.
Van der Waals interactions result when
1. hydrid orbitals overlap.
2. electrons are not symmetrically distributed in a molecule.
3. molecules held by ionic bonds react with water.
4. two polar covalent bonds react.
5. a hydrogen atom loses an electron.
Which of the following is NOT considered a weak molecular interaction?
1. covalent bond
2. van der Waals interactions
3. ionic bond in the presence of water
4. hydrogen bond
5. non answer is correct.