Deck 2: Essential Chemistry for Biology

Question 1

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.

Answer 1

C

Question 2

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

Answer 2

A

Question 3

The four most common elements found in living organisms are ________.

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

Answer 3

B

Question 4

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

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

Question 5

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 6

An atom's ________ are found in its nucleus.

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

Question 7

In the following reaction,what type of bond is holding the two atoms together? K+Cl → K⁺ + Cl− → KCl

A) hydrophilic
B) ionic
C) hydrophobic
D) covalent

Question 8

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

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

Question 9

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

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

Question 10

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

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

Question 11

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 12

Adjacent water molecules are joined by ________ bonds.

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

Question 13

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

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

Question 14

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

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

Question 15

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

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

Question 16

An uncharged atom of gold has an atomic number of 79 and an atomic mass of 197.This atom has ________ protons,________ neutrons,and ________ electrons.

A) 79... 118... 79
B) 118... 79... 118
C) 118... 276... 118
D) 79... 34... 79

Question 17

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 18

________ is an example of an element.

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

Question 19

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

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

Question 20

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

Question 21

As water freezes,________.

A) its molecules move farther apart
B) it cools the surrounding environment
C) its hydrogen bonds break apart
D) it loses its polarity

Question 22

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

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

Question 23

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

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

Question 24

The lower the pH of a solution,the ________.

A) greater the number of oxygen atoms
B) more acidic the solution
C) less toxic the solution
D) higher the OH- concentration

Question 25

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 26

All of the representations in the following figure EXCEPT one clearly show double bonds.Choose the exception.

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

Question 27

Adjacent water molecules are connected by 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 28

Examine the drawing of an atom below.The art is technically INCORRECT in that ________.

A) neutrons are not located in the nucleus
B) the electrons should be much farther away from the nucleus
C) electrons do not orbit the nucleus
D) electrons do not have a negative charge

Question 29

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) O₂ ₒnlᵧ
D) C₆H₁₂O₆, H₂O, O₂, CO₂, and H₂O

Question 30

Which of the following is an acid?

A) NaOH
B) NaCl
C) HCl
D) CH₄

Question 31

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

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

Question 32

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

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

Question 33

Examine the pH scale below.How does household bleach compare to household ammonia?

A) Household ammonia has 100 times higher H⁺ concentration than household bleach.
B) Household bleach has 10 times higher H⁺ concentration than household ammonia.
C) Household bleach has 100 times higher H⁺ concentration than household ammonia.
D) Household ammonia has 10 times higher H⁺ concentration than household bleach.

Question 34

Sweating cools your body by ________.

A) cohesion
B) radiation
C) evaporative cooling
D) hydrogen bonding

Question 35

Why (if you are careful)are you able to float a needle on the surface of water?

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 needle is less dense than water.

Question 36

Human body cells are approximately ________ water.

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

Question 37

A base ________.

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

Question 38

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 39

Which of the following is NOT a potential impact of ocean acidification?

A) Decreasing H⁺ concentrations
B) Coral bleaching
C) Changes in metabolism of marine animals
D) Increasing carbonic acid concentrations

Question 40

Relative to a pH of 6,a pH of 4 has a ________.

A) 200 times higher H⁺ concentration
B) 100 times higher H⁺ concentration
C) 20 times higher H⁺ concentration
D) 100 times lower H⁺ concentration

Question 41

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.
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 42

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 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.

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 44

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.

Using the table above,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 45

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 her tumor is destroyed.

Question 46

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