Week 2 (Chapter 3 - Chemistry of Life)

An example of an element would be: A. Ne B. CO2 C. C6H12O6 D. H2O

A. Ne

The most abundant element essential to life is A. carbon B. oxygen C. hydrogen D. nitrogen

A. carbon

A weak acid: A. dissociates very little in solution. B. dissociates almost completely in solution. C. will cause the pH of the solution to rise above 7. D. does both B and C.

A. dissociates very little in solution. - A weak acid, on the other hand, dissociates very little and therefore produces few excess H ions in solution. There are many important acids in the body, and they perform many functions. - A strong acid, an acid that completely, or almost completely, dissociates to form H ions. - A base to a solution will cause the pH of the solution to rise above 7.

As the concentration of hydrogen ions increases, the pH goes _____, and the solution becomes more _____. A. down; acidic B. down; alkaline C. up; acidic D. up; alkaline

A. down; acidic - As the concentration of hydrogen ions increases, the pH goes down, and the solution becomes more acidic.

An atom can be described as chemically inert if its outermost electron shell contains _____ electrons. A. eight B. nine C. two D. Both A and C are correct.

A. eight - An atom can be described as chemically inert if its outermost electron shell, also known as the valence shell, contains 8 electrons. This is known as the octet rule.

When atoms combine, they may gain, lose, or share: A. electrons B. protons C. neutrons D. nuclei

A. electrons

An example of a catabolic process is: A. hydrolysis B. dehydration synthesis C. formation of a peptide bond D. both B and C

A. hydrolysis

As a result of which reaction during catabolism is a water molecule added to break a larger compound into smaller subunits? A. hydrolysis B. dehydration synthesis C. anabolism D. exchange reaction

A. hydrolysis - As a result of hydrolysis occurring during catabolism, a water molecule is added to break a larger compound into smaller subunits.

The atomic number tells you the: A. number of protons in the nucleus. B. number of neutrons in the nucleus. C. number of electrons. D. weight of the atom.

A. number of protons in the nucleus. - The number of protons in an atom's nucleus, called its atomic number, it identifies the kind of element it is.

The kind of element is determined by the number of: A. protons B. neutrons C. mesotrons D. electrons

A. protons

Acids A. release hydrogen ions. B. have a pH above 7. C. take up hydroxyl ions. D. release hydrogen ions and have a pH above 7.

A. release hydrogen ions.

The type of chemical reaction most likely to require energy is a(n) _____ reaction. A. synthesis B. decomposition C. exchange D. All of the above reactions are equally likely to require energy.

A. synthesis - Synthesis reactions result in the formation of new bonds, and energy is required for the reaction to occur and the new product to form.

Carbon has an atomic number of 6. The number of electrons found in the first shell is: A. two B. four C. six D. eight

A. two

Approximately what percentage of the body weight of an adult female is water? A. 40% B. 50% C. 60% D. 70%

B. 50%

The process of the digestion of food is an example of which type of reaction? A. Synthesis B. Decomposition C. Exchange D. Reversible

B. Decomposition

Which of the following elements is least likely to combine with another element? A. Hydrogen B. Helium C. Oxygen D. Carbon

B. Helium

Which of the following bonds are the weakest? A. Ionic B. Hydrogen C. Electrovalent D. Covalent

B. Hydrogen

Which of the following is not one of the major elements present in the human body? A. Oxygen B. Zinc C. Carbon D. Potassium

B. Zinc

A solution that contains a greater concentration of hydroxide ions (OH-) than hydrogen ions (H+) is a(n) _____ solution. A. acidic B. alkaline (basic) C. neutral D. Not enough information is given to determine the character of the solution.

B. alkaline (basic)

Substances that accept hydrogen ions are called: A. acids B. bases C. buffers D. salts

B. bases

A force holding two atoms together is a(n) A. isotope B. chemical bond C. energy shell D. isomer

B. chemical bond - A force holding two atoms together is a chemical bond. A chemical bond is an attractive force that holds two or more atoms together in a molecule or compound. These bonds are formed when electrons are shared, transferred, or redistributed between atoms, leading to a stable arrangement of atoms in the molecule or compound.

Chemical bonds formed by the sharing of electrons are called: A. ionic B. covalent C. hydrogen D. isotopic

B. covalent

The element oxygen has an atomic number of 8, which means it contains: A. four protons and four neutrons B. eight protons C. eight neutrons D. four protons and four electrons

B. eight protons - the number of protons is the same number as the atomic number of that element.

A substance that cannot be broken down or decomposed into two or more different substances is called a(n) A. atom B. element C. compound D. isotope

B. element - An element is said to be "pure" in the sense that it cannot be broken down or decomposed into two or more different substances. Carbon and oxygen are good examples of elements.

AB + CD → AD + CB is an example of a(n) _____ reaction. A. synthesis B. exchange C. decomposition D. reversible

B. exchange

What decomposition reaction requires the addition of a water molecule to break a bond? A. dehydration synthesis B. hydrolysis C. catalysis D. disulfide linkage

B. hydrolysis - Hydrolysis is a chemical reaction that breaks down complex molecules into simpler ones by adding a water molecule. This process requires splitting the water molecule into a proton and a hydroxide ion, which are then used to break the chemical bond. - An example of hydrolysis is table sugar (which is called sucrose) can be broken down into two smaller sugar pieces called glucose and fructose by adding water. It's like breaking a big cookie into two smaller pieces by adding some water to it.

Atoms with fewer than eight electrons in the outer energy level will attempt to lose, gain, or share electrons with other atoms to achieve stability. This tendency is called the A. atomic rule. B. octet rule. C. electrovalent principle. D. tertiary rule.

B. octet rule.

Hydrogen bonds result from unequal charge distribution on a molecule. Such molecules are said to be A. nonpolar B. polar C. covalent D. ionic

B. polar - nonpolar molecules have an even distribution of charge and do not form hydrogen bonds. - covalent bond is a type of chemical bond that involves the sharing of electrons between two or more atoms. - Ionic bond is a type of chemical bond that involves the transfer of electrons from one atom to another.

As the concentration of hydrogen ions (H+) increases, the: A. solution becomes more basic B. solution becomes more acidic C. pH rises D. Both A and C are correct

B. solution becomes more acidic

The octet rule refers to the: A. stability of the nucleus when the protons are in a multiple of eight. B. stability of the atom when there are eight electrons in the outermost energy level. C. stable configuration of the nucleus when there are eight more neutrons than protons. D. principle that one atom can combine with a maximum of eight other atoms.

B. stability of the atom when there are eight electrons in the outermost energy level.

The reaction between hydrogen and oxygen needed to form water is an example of a: A. hydrogen bond. B. synthesis reaction C. decomposition reaction D. None of the above is correct

B. synthesis reaction - In synthesis reactions, two or more substances called reactants combine to form a different, more complex substance called a product. Synthesis literally means "putting together."

In the presence of a base, red litmus paper will: A. stay red B. turn blue C. turn green D. turn yellow

B. turn blue

The most abundant and important compound(s) in the body is(are): A. air B. water C. proteins D. nucleic acids

B. water

A magnesium atom has an atomic number of 12, an atomic mass of 25, and a +2 charge. This atom would contain _____ protons, _____ neutrons, and _____ electrons. A. 12; 25; 2 B. 12; 13; 14 C. 12; 13; 10 D. Not enough information is given to answer the question

C. 12; 13; 10

The atomic number of carbon is 6. How many unpaired electrons are in its outer shell? A. Two B. Three C. Four D. Five

C. Four

Which of the following represents a trace element in the body? A. Sulfur B. Chlorine C. Iron D. Phosphorus

C. Iron

Which subatomic particles carry a charge? A. Protons and neutrons B. Neutrons and electrons C. Protons and electrons D. Neutrons only

C. Protons and electrons

Which of the following is not a subatomic particle? A. Proton B. Electron C. Radon D. Neutron

C. Radon - types of subatomic particles: • Protons (+) • Neutrons (neutral 0) • Electrons (-)

An ionic bond is formed by: A. two or more positive ions combining B. two or more negative ions combining C. a positive and a negative ion attracting each other D. sharing of a pair of electrons

C. a positive and a negative ion attracting each other

Electrolytes are: A. organic compounds B. called cations if they have a negative charge. C. called cations if they have a positive charge. D. both A and B.

C. called cations if they have a positive charge.

A chemical bond formed by the sharing of one or more pairs of electrons between the outer shells of two atoms is called a(n) _____ bond. A. ionic B. hydrogen C. covalent D. none of the above

C. covalent

Acids, bases, and salts belong to a large group of compounds called A. polar molecules. B. organic compounds. C. electrolytes D. nonelectrolytes

C. electrolytes - Acids, bases, and salts belong to a large group of compounds called electrolytes. - When acids dissolve in water, they make positively charged hydrogen ions (H+). Bases, on the other hand, make negatively charged hydroxide ions (OH-) when they dissolve in water. Salts are compounds that form when an acid and a base react with each other. Salts are important in many chemical reactions and in our bodies, where they help keep things balanced and move things around in cells.

An element that contains the same number of protons but different numbers of neutrons is called a(n) A. ion B. isomer C. isotope D. bond

C. isotope

For sodium to transform from a neutral atom to a positive ion, it must: A. gain an electron B. gain a proton. C. lose an electron. D. lose a proton.

C. lose an electron. - In an atom of sodium, there are both positively charged protons and negatively charged electrons. Normally, these charges balance out, resulting in a neutral atom with no overall charge. But when sodium loses an electron, the balance is disrupted, and there are more positively charged protons than negatively charged electrons. This creates a net positive charge, turning the neutral sodium atom into a positively charged ion. When sodium loses an electron, it's like one of the participants on the negative charge team lets go, causing the positive charge team to win and resulting in a net positive charge for the sodium ion.

What term is used to describe all of the chemical reactions that occur in body cells? A. catabolism B. anabolism C. metabolism D. morphism

C. metabolism - The term used to describe all of the chemical reactions that occur in body cells is metabolism. Metabolism refers to the set of chemical processes that take place in living organisms to maintain life, including the conversion of food into energy, the synthesis of new molecules, and the breakdown of waste products. - Metabolism can be divided into two categories: catabolism, which involves the breakdown of larger molecules into smaller ones to release energy, and anabolism, which involves the synthesis of larger molecules from smaller ones using energy.

An isotope of an element contains different numbers of ____ from other atoms of the same element. A. electrons B. protons C. neutrons D. both protons and neutrons

C. neutrons

The total number of electrons in a neutral atom equals the number of: A. neutrons orbiting the atom. B. protons plus the number of neutrons in its nucleus. C. protons in its nucleus. D. ions in its nucleus.

C. protons in its nucleus. - The total number of electrons (-) in an atom equals the number of protons (+) in its nucleus. These electrons are known to exist in regions surrounding the atom's nucleus.

The type of reaction in which substances are combined to form more complex substances is called a(n) _____ reaction. A. reversible B. exchange C. synthesis D. decomposition

C. synthesis

Ionic bonds are chemical bonds formed by the: A. sharing of electrons between molecules. B. donation of protons from one atom to another. C. transfer of electrons from one atom to another. D. acceptance of neutrons from one atom by another.

C. transfer of electrons from one atom to another. - A chemical bond formed by the transfer of electrons from one atom to another is called an ionic, or electrovalent, bond.

The approximate pH of gastric fluid is: A. 10 B. 8 C. 4 D. 2

D. 2

The elements carbon, hydrogen, oxygen, and nitrogen make up which percentage of the human body? A. 50% B. 69% C. 78% D. 96%

D. 96% - There are 11 major elements, 4 of which (carbon, oxygen, hydrogen, and nitrogen) make up 96% of the human body

Which of the following represents properties of water? A. High specific heat B. High heat of vaporization C. Strong polarity D. All of the above

D. All of the above

Salts: A. can form as the result of a chemical reaction between acids and bases. B. are electrolytes. C. will form crystals if the water is removed. D. All of the above are correct.

D. All of the above are correct. - can form as the result of a chemical reaction between acids and bases. - are electrolytes - will form crystals if the water is removed

Acids: A. are proton donors. B. taste sour. C. release hydrogen ions in an aqueous solution. D. All of the above are true of acids.

D. All of the above are true of acids.

As the concentration of hydroxide ions (OH-) increases, the: A. solution becomes more basic. B. solution becomes more acidic. C. pH rises. D. Both A and C are correct.

D. Both A and C are correct. - solution becomes more basic. - pH rises. - As the concentration of hydroxide ions (OH-) increases, the solution becomes more basic or pH rises (alkaline).

The study of metabolism includes examination of: A. catabolism B. anabolism C. ATP requirements D. all of the above

D. all of the above

The study of metabolism includes examination of: A. catabolism B. anabolism C. ATP requirements D. all of the above

D. all of the above - catabolism - anabolism - ATP requirements

Hydrolysis _____ a water molecule. A. joins compounds by removing B. breaks down compounds by removing C. joins compounds by adding D. breaks down compounds by adding

D. breaks down compounds by adding

Which type of chemical reaction results in the breakdown of a complex substance into two or more simpler substances? A. exchange reaction B. synthesis reaction C. reversible reaction D. decomposition reaction

D. decomposition reaction

The formation of sucrose involves the removal of a molecule of water. This is called: A. hydrolysis B. oxidation C. decomposition D. dehydration synthesis

D. dehydration synthesis

A negatively charged subatomic particle that moves around the nucleus is a(n): A. orbital B. proton C. neutron D. electron

D. electron

A molecule that is polar: A. can form a hydrogen bond. B. must be ionic. C. has an unequal charge. D. is both A and C.

D. is both A and C. - can form a hydrogen bond - has an unequal charge

The hydrogen isotope tritium consists of: A. one proton B. one proton and one neutron C. two protons and one neutron D. one proton and two neutrons

D. one proton and two neutrons

The water molecule has two distinct ends, each with a partial electrical charge. Because of this structure, water is said to be A. liquid B. solvent C. neutralized D. polar

D. polar

Atomic mass is determined by the number of: A. protons and electrons B. neutrons and electrons C. neutrons, protons, and electrons D. protons and neutrons

D. protons and neutrons