Question 1

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)    C) A) and B)
D) undefined

Question 2

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.E) B) and D)
F) None of the above

Question 3

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 4

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, #2E) All of the above
F) A) and D)

Question 5

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.F) B) and D)
G) A) and D)

Question 6

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...

Question 7

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.F) B) and E)
G) B) and D)

Question 8

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.F) A) and E)
G) C) and E)

Question 9

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.F) A) and E)
G) A) and D)

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

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 12

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, tearsF) B) and E)
G) A) and B)

Question 13

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 1F) A) and B)
G) A) and C)

Question 14

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)   52E) A) and B)
F) A) and C)

Question 15

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 atomsF) B) and E)
G) A) and E)

Question 16

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 17

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.E) C) and D)
F) A) and B)

Question 18

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.E) None of the above
F) B) and D)

Exam 2: Basic Chemistry

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

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

Correct Answer
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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.

Correct Answer
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The molecular formula is H₂. A nonpolar c...
View Answer

Which statement is NOT true about polar covalent bonds?

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

Correct Answer
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A valence shell is best described as

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

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

Correct Answer
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In a water molecule,

Correct Answer
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How many atoms are required to form a molecule?

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

Correct Answer
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Correct Answer
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Argon has an outer shell with ...
View Answer

Which statement is NOT true about covalent bonds?

Correct Answer
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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.

Correct Answer
verified
Sodium donates an electron to chlorine t...
View Answer

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?

Correct Answer
verified

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

Correct Answer
verified

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

Correct Answer
verified

As a solid, water floats. This means that

Correct Answer
verified

Exam 2: Basic Chemistry

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedThe molecular formula is H2. A nonpolar c...View AnswerShow Answer

Which statement is NOT true about polar covalent bonds?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A valence shell is best described as

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In a water molecule,

Correct AnswerverifiedShow Answer

How many atoms are required to form a molecule?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct AnswerverifiedArgon has an outer shell with ...View AnswerShow Answer

Which statement is NOT true about covalent bonds?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedSodium donates an electron to chlorine t...View AnswerShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

As a solid, water floats. This means that

Correct AnswerverifiedShow Answer

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified
The molecular formula is H₂. A nonpolar c...
View Answer

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
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Correct Answer
verified
Argon has an outer shell with ...
View Answer

Correct Answer
verified

Correct Answer
verified
Sodium donates an electron to chlorine t...
View Answer

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified