Campbell Biology Chapter 2 Final
Exam Questions And All Correct
Answers.
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25
elements make up approximately 96% of living matter? - Answer carbon, hydrogen, nitrogen,
oxygen
Trace elements are those required by an organism in only minute quantities. Which of the
following is a trace element that is required by humans and other vertebrates, but not by other
organisms such as bacteria or plants? - Answer iodine
Which of the following statements is false?
1.Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter
2. some trace elements are very abundant on Earth
3. virtually all organisms require the same elements in the same quantities
4. iron is an example of an element needed y all organisms
5. other than some trace elements, animals are mostly made up of the same elements as plants,
in similar proportions - Answer virtually all organisms require the same elements in the same
quantities
What factors are most important in determining which elements are most common in living
matter? - Answer both the relative abundances of the elements and the emergent properties
of the compounds made from these elements
Why is each element unique and different from other elements in chemical properties? -
Answer each element has a unique number of protons in its nucleus
knowing just the atomic mass of an element allows inferences about which of the following? -
Answer the number of protons plus neutrons in the element
in what way are elements in the same column of the periodic table the same? - Answer they
have the same number of electrons in their valence shell
, the nucleus of nitrogen atom contains 7 neutrons and 7 protons. which of the following is a
correct statement concerning nitrogen? - Answer the nitrogen atom has a mass number of 14
and an atomic mass of approximately 14 daltons
molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers
of 92, 94, 95, 96, 97, 98, and 100. Therefore, which of the following can be true? - Answer
molybdenum atoms can have between 50 and 58 neutrons
carbon-12 is the most common isotope of carbon, and has an atomic mass of 12 daltons. a mole
of carbon in naturally occurring coal, however, weighs slightly more than 12 grams. Why? -
Answer some carbon atoms in nature have more neutrons
Atom 1 Atom 2
13
11
HH
Which of the following best describes the relationship between the atoms described above? -
Answer they are isotopes
the precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the
standard atomic mass, or even from sample to sample. Why? - Answer the element may have
multiple stable isotopes, and the isotopic composition may vary from sample to sample
one different between carbon-12 (12/6 C) is the carbon-14 (14/6 C) has - Answer two more
neutrons than carbon-12
an atom has 6 electrons in its outer shell. how many unpaired electrons does it have? - Answer
2
the atomic number of nitrogen is 7. nitrogen-15 is heavier than nitrogen-14 because the atomic
nucleus of nitrogen-15 contains how many neutrons? - Answer 8
electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient
energy, a possible result is that - Answer an electron may move to an electron shell farther
Exam Questions And All Correct
Answers.
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25
elements make up approximately 96% of living matter? - Answer carbon, hydrogen, nitrogen,
oxygen
Trace elements are those required by an organism in only minute quantities. Which of the
following is a trace element that is required by humans and other vertebrates, but not by other
organisms such as bacteria or plants? - Answer iodine
Which of the following statements is false?
1.Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter
2. some trace elements are very abundant on Earth
3. virtually all organisms require the same elements in the same quantities
4. iron is an example of an element needed y all organisms
5. other than some trace elements, animals are mostly made up of the same elements as plants,
in similar proportions - Answer virtually all organisms require the same elements in the same
quantities
What factors are most important in determining which elements are most common in living
matter? - Answer both the relative abundances of the elements and the emergent properties
of the compounds made from these elements
Why is each element unique and different from other elements in chemical properties? -
Answer each element has a unique number of protons in its nucleus
knowing just the atomic mass of an element allows inferences about which of the following? -
Answer the number of protons plus neutrons in the element
in what way are elements in the same column of the periodic table the same? - Answer they
have the same number of electrons in their valence shell
, the nucleus of nitrogen atom contains 7 neutrons and 7 protons. which of the following is a
correct statement concerning nitrogen? - Answer the nitrogen atom has a mass number of 14
and an atomic mass of approximately 14 daltons
molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers
of 92, 94, 95, 96, 97, 98, and 100. Therefore, which of the following can be true? - Answer
molybdenum atoms can have between 50 and 58 neutrons
carbon-12 is the most common isotope of carbon, and has an atomic mass of 12 daltons. a mole
of carbon in naturally occurring coal, however, weighs slightly more than 12 grams. Why? -
Answer some carbon atoms in nature have more neutrons
Atom 1 Atom 2
13
11
HH
Which of the following best describes the relationship between the atoms described above? -
Answer they are isotopes
the precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the
standard atomic mass, or even from sample to sample. Why? - Answer the element may have
multiple stable isotopes, and the isotopic composition may vary from sample to sample
one different between carbon-12 (12/6 C) is the carbon-14 (14/6 C) has - Answer two more
neutrons than carbon-12
an atom has 6 electrons in its outer shell. how many unpaired electrons does it have? - Answer
2
the atomic number of nitrogen is 7. nitrogen-15 is heavier than nitrogen-14 because the atomic
nucleus of nitrogen-15 contains how many neutrons? - Answer 8
electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient
energy, a possible result is that - Answer an electron may move to an electron shell farther
