Question 1

Which statement is NOT true about covalent bonds?

Accepted Answer

A)  Covalent bonds form when an electron is completely lost or gained from an atom. 
B)  A covalent molecule contains one or more covalent bonds. 
C)  A single covalent bond is drawn as a line between two atoms. 
D)  A pair of electrons is shared between two atoms for each covalent bond. 
E)  Shared electrons allow an atom to complete its outer electron shell in a covalent molecule. 
A)  Covalent bonds form when an electron is completely lost or gained from an atom. 
B)  A covalent molecule contains one or more covalent bonds. 
C)  A single covalent bond is drawn as a line between two atoms. 
D)  A pair of electrons is shared between two atoms for each covalent bond. 
E)  Shared electrons allow an atom to complete its outer electron shell in a covalent molecule.

Question 2

How many atoms are required to form a molecule?

Accepted Answer

A)  at least 2 
B)  at least 3 
C)  at least 4 
D)  at least 5 
E)  only 1 
A)  at least 2 
B)  at least 3 
C)  at least 4 
D)  at least 5 
E)  only 1

Question 3

A valence shell is best described as

Accepted Answer

A)  the electron shell closest to the nucleus. 
B)  the outermost electron shell of an atom. 
C)  the volume of space in which electrons are most often found. 
D)  the original energy level of electrons in photosynthesis. 
A)  the electron shell closest to the nucleus. 
B)  the outermost electron shell of an atom. 
C)  the volume of space in which electrons are most often found. 
D)  the original energy level of electrons in photosynthesis.

Question 4

A research article indicates that researchers have used an isotope 3H to trace a certain metabolic process. From the symbol that is given, we know this is a hydrogen isotope with

Accepted Answer

A)  three protons. 
B)  three neutrons. 
C)  three electrons. 
D)  one proton and two neutrons. 
E)  two protons and one neutron. 
A)  three protons. 
B)  three neutrons. 
C)  three electrons. 
D)  one proton and two neutrons. 
E)  two protons and one neutron.

Question 5

The mass number refers to the number of ______ and ______ within an element.

Accepted Answer

A)  protons and neutrons 
B)  protons and electrons 
C)  electrons and neutrons 
D)  protons and molecules 
E)  electrons and atoms 
A)  protons and neutrons 
B)  protons and electrons 
C)  electrons and neutrons 
D)  protons and molecules 
E)  electrons and atoms

Question 6

Following nitrogen (78%) and oxygen (21%), argon is the next most common gas in the atmosphere (less than 1%). Checking the table of elements, you discover that argon is one of a family of atoms with outer shells already full of electrons. How is this related to the fact that these atoms have virtually no biological importance?

Accepted Answer

Argon has an outer shell with

Question 7

In a water molecule,

Accepted Answer

A)  the oxygen atom is more electronegative than the hydrogen atoms. 
B)  the oxygen atom has an overall negative charge with the hydrogen atoms having an overall positive charge. 
C)  unequal sharing of electrons results in a polar molecule. 
D)  All of the choices are correct. 
A)  the oxygen atom is more electronegative than the hydrogen atoms. 
B)  the oxygen atom has an overall negative charge with the hydrogen atoms having an overall positive charge. 
C)  unequal sharing of electrons results in a polar molecule. 
D)  All of the choices are correct.

Question 8

What does this graph reveal about the heat of vaporization and the heat of fusion?

Accepted Answer

The answer of What does this graph reveal about the...

Question 9

This system of chemicals,   , act as a buffer in the blood. If hydrogen ions are added to blood which of the following reactions would occur?

Accepted Answer

A)    
B)      
A)    
B)

Question 10

If the atomic number of an element is 6 and the atomic mass is 12.01, how many protons are there in the nucleus?

Accepted Answer

A)  12 
B)  6 
C)  24 
D)  52 
A)  12 
B)  6 
C)  24 
D)  52

Question 11

Which statement is NOT true about polar covalent bonds?

Accepted Answer

A)  Most covalent bonds are nonpolar, with electrons shared fairly equally between the atoms. 
B)  Polar covalent bonds are important in the characteristics of water. 
C)  Electrons are shared unequally in a polar covalent bond. 
D)  The larger atom in a polar bond attracts the electron more strongly than the smaller atom. 
E)  The oxygen of a water molecule is electropositive relative to the hydrogen. 
A)  Most covalent bonds are nonpolar, with electrons shared fairly equally between the atoms. 
B)  Polar covalent bonds are important in the characteristics of water. 
C)  Electrons are shared unequally in a polar covalent bond. 
D)  The larger atom in a polar bond attracts the electron more strongly than the smaller atom. 
E)  The oxygen of a water molecule is electropositive relative to the hydrogen.

Question 12

Draw two hydrogen atoms using Bohr's model. Now bond them to form a molecule of hydrogen gas. Write the molecular formula. Explain what type of bond you've created and why this is a stable situation.

Accepted Answer

The molecular formula is H₂. A nonpolar c

Question 13

Which of the following elements would be the most reactive with other elements?

Accepted Answer

A)  boron, #5 
B)  neon, #10 
C)  argon, #18 
D)  helium, #2 
A)  boron, #5 
B)  neon, #10 
C)  argon, #18 
D)  helium, #2

Question 14

Which substances are on the basic side of the pH scale?

Accepted Answer

A)  baking soda, oven cleaner and human blood 
B)  baking soda, oven cleaner and urine 
C)  tomatoes, oven cleaner and human blood 
D)  beer, vinegar and black coffee 
E)  Great Salt Lake, oven cleaner, tears 
A)  baking soda, oven cleaner and human blood 
B)  baking soda, oven cleaner and urine 
C)  tomatoes, oven cleaner and human blood 
D)  beer, vinegar and black coffee 
E)  Great Salt Lake, oven cleaner, tears

Question 15

Both 18O and 16O are found in nature. However, 16O is the most common. Therefore,

Accepted Answer

A)  these are different elements. 
B)  oxygen atoms can have eight or 10 neutrons. 
C)  18O has two additional electrons in its outer shell. 
D)  18O is the form of oxygen that provides living cells with life. 
E)  only the common form of 16O can bond with hydrogen atoms to form H2O. 
A)  these are different elements. 
B)  oxygen atoms can have eight or 10 neutrons. 
C)  18O has two additional electrons in its outer shell. 
D)  18O is the form of oxygen that provides living cells with life. 
E)  only the common form of 16O can bond with hydrogen atoms to form H2O.

Question 16

The scale indicates the relative concentrations of hydrogen and hydroxyl ions in a solution.

Accepted Answer

A) True 
 B)False

Question 17

As a solid, water floats. This means that

Accepted Answer

A)  solid water is less dense than liquid water. 
B)  organisms in ponds, lakes, and reservoirs can survive under the ice cover. 
C)  this is due to hydrogen bonding changes. 
D)  All of the choices are correct. 
A)  solid water is less dense than liquid water. 
B)  organisms in ponds, lakes, and reservoirs can survive under the ice cover. 
C)  this is due to hydrogen bonding changes. 
D)  All of the choices are correct.

Question 18

Use Bohr's model to draw a sodium (Na) atom and a chlorine (Cl) atom. Using your model, explain what happens when sodium reacts with chlorine to form table salt. Include in your explanation ion and ionic bond formation. Use your model to help you to decide whether NaCl is hydrophilic or hydrophobic.

Accepted Answer

Sodium donates an electron to chlorine t

Exam 2: Basic Chemistry

Which statement is NOT true about covalent bonds?

How many atoms are required to form a molecule?

A valence shell is best described as

A research article indicates that researchers have used an isotope 3H to trace a certain metabolic process. From the symbol that is given, we know this is a hydrogen isotope with

The mass number refers to the number of ______ and ______ within an element.

In a water molecule,

What does this graph reveal about the heat of vaporization and the heat of fusion?

This system of chemicals, , act as a buffer in the blood. If hydrogen ions are added to blood which of the following reactions would occur?

If the atomic number of an element is 6 and the atomic mass is 12.01, how many protons are there in the nucleus?

Which statement is NOT true about polar covalent bonds?

Draw two hydrogen atoms using Bohr's model. Now bond them to form a molecule of hydrogen gas. Write the molecular formula. Explain what type of bond you've created and why this is a stable situation.

Which of the following elements would be the most reactive with other elements?

Which substances are on the basic side of the pH scale?

Both 18O and 16O are found in nature. However, 16O is the most common. Therefore,

The scale indicates the relative concentrations of hydrogen and hydroxyl ions in a solution.

As a solid, water floats. This means that

A View of Life

The Chemistry of Organic Molecules

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Metabolism: Energy and Enzymes

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Mendelian Patterns of Inheritance

Molecular Biology of the Gene

Regulation of Gene Expression

Biotechnology and Genomics

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Origin and History of Life

Taxonomy, Systematics, and Phylogeny

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Protist Evolution and Diversity

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Flowering Plants: Reproduction

Invertebrate Evolution

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Human Evolution

Animal Organization and Homeostasis

Circulation and Cardiovascular Systems

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Digestive Systems and Nutrition

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Filters

A research article indicates that researchers have used an isotope ³H to trace a certain metabolic process. From the symbol that is given, we know this is a hydrogen isotope with

The mass number refers to the number of and within an element.

Both ¹⁸O and ¹⁶O are found in nature. However, ¹⁶O is the most common. Therefore,