Deck 2: Essential Chemistry for Biology

Question 1

An atom with an electrical charge is a(n)________.

A)isotope
B)molecule
C)ion
D)compound

Answer 1

C

Question 2

The way Earth moves about the sun is most like ________.

A)a neutron and electron moving around a proton
B)an electron moving around the nucleus of an atom
C)a proton moving about an electron
D)a neutron moving about a proton

Answer 2

B

Question 3

An atom's ________ are found in its nucleus.

A)neutrons and protons
B)protons only
C)neutrons and electrons
D)electrons, protons, and neutrons

Answer 3

A

Question 4

All atoms of an element have the same number of ________.

A)protons plus neutrons
B)protons
C)electrons
D)neutrons

Question 5

What are the four most common elements found in living organisms?

A)nitrogen, oxygen, phosphorus, and carbon
B)carbon, oxygen, nitrogen, and hydrogen
C)carbon, oxygen, potassium, and calcium
D)oxygen, calcium, hydrogen, and carbon

Question 6

Sulfur has an atomic number of 16. How many covalent bonds can sulfur form?

A)1
B)2
C)4
D)0

Question 7

Adjacent water molecules interact with one another via ________ bonds.

A)covalent only
B)ionic
C)polar and covalent
D)hydrogen

Question 8

Which of the following elements is a trace element that is essential to life?

A)phosphorus
B)carbon
C)iron
D)calcium

Question 9

Why is water considered a polar molecule?

A)The oxygen atom is found between the two hydrogen atoms.
B)The oxygen atom attracts the hydrogen atoms.
C)The oxygen end of the molecule has a slight negative charge, and the hydrogen end has a slight positive charge.
D)Both hydrogen atoms are at one end of the molecule, and the oxygen atom is at the other end.

Question 10

The bond between oppositely charged ions is a(n)________ bond.

A)ionic
B)polar
C)hydrogen
D)covalent

Question 11

In order to have a positive charge, an atom must have ________.

A)more protons than electrons
B)more electrons than protons
C)more neutrons than protons
D)more protons than neutrons

Question 12

________ is an example of an element.

A)Water
B)Nitrogen
C)Glucose
D)Salt

Question 13

What name is given to bonds that involve the sharing of electrons?

A)covalent
B)hydrogen
C)ionic
D)polar

Question 14

How do radioactive isotopes differ from isotopes?

A)Radioactive isotopes have more neutrons than do isotopes.
B)Radioactive isotopes are stable; isotopes are unstable.
C)Radioactive isotopes have fewer neutrons than do isotopes.
D)Radioactive isotopes are unstable; isotopes are stable.

Question 15

Beryllium's atomic mass is 9, and its atomic number is 4. How many protons are found in a beryllium atom?

A)9
B)13
C)4
D)5

Question 16

The hydrogen and oxygen atoms of a water molecule are held together by ________ bonds.

A)ionic
B)hydrogen
C)covalent
D)polar

Question 17

Consider the following reaction. What type of bond is holding the two atoms together? K + Br → K⁺ + Br⁻ → KBr

A)covalent
B)ionic
C)hydrogen

Question 18

How can radiation be controlled and safely used in medicine?

A)Apply radiation throughout the body at uncontrolled doses.
B)Apply radiation throughout the body at controlled doses.
C)Apply radiation to specific parts of the body at uncontrolled doses.
D)Apply radiation to specific parts of the body at controlled doses.

Question 19

An uncharged atom of mercury has an atomic number of 80 and an atomic mass of 200. This atom has ________ protons, ________ neutrons, and ________ electrons.

A)80; 120; 80
B)120; 80; 120
C)120; 280; 120
D)80; 40; 80

Question 20

Isotopes of an element have the same number of ________ and different numbers of ________.

A)protons; neutrons
B)protons; electrons
C)neutrons; protons
D)electrons; protons

Question 21

Which of the following is an acid?

A)NaOH
B)NaCl
C)HCl
D)CH₄

Question 22

How many oxygen atoms are in the products of the following reaction? C₆H₁₂O₆ + 6 H₂O + 6 O₂ → 6 CO₂ + 12 H₂O

A)18
B)6
C)12
D)24

Question 23

Radiometric dating is based on ________.

A)the number of electrons in atoms
B)the decay of radioactive isotopes
C)the strength of bonds holding together atoms
D)the rates of chemical reactions

Question 24

What are the reactant(s)in the following chemical reaction? C₆H₁₂O₆ + 6 H₂O + 6 O₂ → 6 CO₂ + 12 H₂O

A)CO₂ and H₂O
B)C₆H₁₂O₆, H₂O, and O₂
C)O_{2 only}
D)C₆H₁₂O₆, H₂O, O_2, CO₂, and H₂O

Question 25

Human body cells are approximately ________ water.

A)95-99%
B)25-35%
C)50-55%
D)70-95%

Question 26

Adjacent water molecules interact through the ________.

A)sharing of electrons between the hydrogen of one water molecule and the oxygen of another water molecule
B)electrical attraction between the hydrogen of one water molecule and the oxygen of another water molecule
C)sharing of electrons between adjacent oxygen molecules
D)electrical attraction between the hydrogen atoms of adjacent water molecules

Question 27

What name is given to substances that resist changes in pH?

A)buffers
B)solutions
C)acids
D)bases

Question 28

The lower the pH of a solution, the ________.

A)the more basic the solution
B)more acidic the solution

Question 29

Relative to a pH of 7, a pH of 4 has a ________.

A)3,000 times higher H⁺ concentration
B)1,000 times higher H⁺ concentration
C)300 times higher H⁺ concentration
D)100 times lower H⁺ concentration

Question 30

The tendency of molecules of the same kind to stick together is called ________.

A)bonding
B)cohesion
C)polarity
D)adhesion

Question 31

What is the outcome of evaporative cooling in the form of sweating?

A)a decrease in blood pH
B)a decrease in air temperature
C)a decrease in body temperature

Question 32

Some tiny insects are able to walk on water. Why?

A)Water has adhesive properties.
B)The surface tension that is a result of water's cohesive properties makes this possible.
C)The covalent bonds that hold a water molecule together make this possible.
D)A single insect is less dense than water.

Question 33

All of the following are potential negative impacts of ocean acidification except one. Choose the exception.

A)decreasing H⁺ concentrations
B)coral bleaching
C)changes in metabolism of marine animals
D)increasing carbonic acid concentrations

Question 34

Sugar dissolves when stirred into coffee. The coffee is the ________, the sugar is the ________, and the sweetened coffee is the ________.

A)solution; solvent; solute
B)solute; solvent; solution
C)solvent; solute; solution
D)solution; solute; solvent

Question 35

What type of cancer is treated with radioactive iodine seeds?

A)breast
B)lung
C)prostate
D)skin

Question 36

When a base is added to a buffered solution, the buffer will ________.

A)donate OH⁻
B)accept water molecules
C)donate H⁺ ions
D)form covalent bonds with the base

Question 37

A base ________.

A)removes H₂O molecules from a solution
B)decreases the pH of a solution
C)removes OH⁻ from a solution
D)removes H⁺ from a solution

Question 38

As water freezes, ________.

A)its molecules move farther apart
B)it cools the surrounding environment
C)its hydrogen bonds break apart
D)the water molecules become less polar

Question 39

An atom has 20 protons, 20 neutrons, and 20 electrons. What atom is being described?

A)neon (atomic number 10)
B)calcium (atomic number 20)
C)zirconium (atomic number 40)
D)neodymium (atomic number 60)

Question 40

A fossil was found and determined by radiometric dating to be 11,400 years old. What is the ratio of carbon-14 to carbon-12 in this fossil compared to its environment?

A)12.5%
B)25%
C)37.5%
D)50%

Question 41

The data below are from three separate studies that tested different treatment options for prostate cancer. Based on these data you might conclude that after 10 years, radioactive seeds are a more effective treatment option than external radiation for prostate cancer. What is a possible confounding factor that could lead to the results below?

A)The men who received external radiation were healthier at the start of the treatment than the men who received radioactive seeds.
B)The men who received external radiation had larger tumors than the men who received radioactive seeds.
C)The men who received radioactive seeds had additional types of cancers whereas the men who received external radiation only had prostate cancer.
D)The men who received radioactive seeds had poor diets compared to the men who received external radiation.

Question 42

The data below are from three separate studies that tested different treatment options for prostate cancer. What can you conclude from these data?

A)The men who were treated with surgery were the healthiest group after 10 years.
B)Cancer progressed the least after 10 years for the men who received external radiation.
C)After 5 years all three treatment options had similar outcomes.
D)After 15 years it is expected that approximately 90% of men who received radiation seeds would have cancer that did not progress.

Question 43

Please read the following scenario to answer the following questions.
While radioactive isotopes are used in medicine to identify tumors and other diseases, they can also be used to treat diseases such as cancer. One method to treat cancerous tumors is to expose them to radiation which can kill the cancerous cells and the tumor. In 2013, the U.S. Food and Drug Administration approved a new cancer treatment based on the radioactive isotope radium-223; this isotope has a half-life of 11.4 days. The radioactive drug, known as Xofigo®, is injected into the patient's bloodstream and travels to certain regions of the body. Because it emits high-energy radiation over short distances, it can kill cancerous cells in the sites where it localizes.
After the drug was injected into a person, the following data were collected regarding the amount of radiation measured in different organs in the person's body.

Which of the following would be the best experiment to determine whether this drug is an effective treatment option for cancer patients?

A)Give the drug to a single cancer patient and ask him how he feels several months later.
B)Give the drug to a group of mice that have artificially induced tumors and measure whether their tumors are destroyed.
C)Give the drug to a group of cancer patients and measure whether their tumors are destroyed.
D)Give the drug to a single cancer patient and measure whether his tumor is destroyed.

Question 44

The graph below shows data regarding radioactive decay of carbon-14. If decay continues to occur normally, how much C-14 will remain after 22,800 years?

A)25%
B)12.5%
C)6)25%
D)3)125%

Question 45

Using the above table, what kind of cancer do you think Xofigo® is used to treat?

A)liver cancer
B)bone cancer
C)brain cancer
D)lung cancer

Question 46

Examine the pH scale below. How does grapefruit juice compare to lemon juice?

A)Grapefruit juice has 100 times higher H⁺ concentration than lemon juice.
B)Lemon juice has 10 times higher H⁺ concentration than grapefruit juice.
C)Lemon juice has 100 times higher H⁺ concentration than grapefruit juice.
D)Grapefruit juice has 10 times higher H⁺ concentration than lemon juice.

Question 47

A cancer patient receives an injection of the drug on March 1. Suppose that the patient must receive a second injection once the amount of the drug decreases to less than 6% in his or her body. On approximately what day should the cancer patient schedule an appointment to receive another injection?

A)March 13
B)March 23
C)April 3
D)April 25

Question 48

In the following figure, all of the representations EXCEPT one clearly show double bonds for the oxygen molecule. Choose the exception.

A)electron configuration
B)structural formula
C)space-filling model
D)ball-and-stick model

Question 49

When Heather grabbed the glass of ice water, the ice cubes were floating at the top. Why were the ice cubes floating in the water?

A)Water can store large amounts of heat.
B)Water can moderate temperatures through evaporative cooling.
C)The density of water decreases when it freezes.
D)Water has a cohesive nature.

Question 50

Please read the following scenario to answer the following questions.
The last few miles of the marathon are the most difficult for Heather. Her hair is plastered to her head, sweat clings to her arms, and her legs feel as if they had nothing left. Heather grabs a cup of ice water. The ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. Then a breeze kicks up and she finally feels some coolness against her skin. Drops of sweat, once clinging to her forehead, now spill down, and Heather feels a stinging as the sweat flows into her eyes.
Why did the sweat on Heather's forehead and arms form drops?

A)because of the high salt content of sweat
B)because of the cohesive nature of water
C)because of the ability of water to moderate heat
D)because of the high evaporative cooling effect of water