Deck 2: Atoms, Ions, and Molecules

Question 1

An atomic nucleus consists of protons and neutrons and is positively charged.

Answer 1

True

Question 2

Which of the following statements accurately describes electrons?

A) They are found inside the nucleus and have a positive charge.
B) They are in orbitals outside the nucleus and have a positive charge.
C) They are found inside the nucleus and have a negative charge.
D) They are in orbitals outside the nucleus and have a negative charge.

Answer 2

D

Question 3

Two atoms that differ only in the number of neutrons they contain are known as

A) anions.
B) isomers.
C) isotopes.
D) ions.

Answer 3

C

Question 4

When diagramming an atom, the innermost shell is filled with ________ electrons.

A) two
B) six
C) eight
D) ten

Question 5

Another name for the outer electron shell of an atom is the ________ shell.

Question 6

Which of the following has the smallest mass?

A) An electron
B) An atomic nucleus
C) A proton
D) A neutron

Question 7

In general, the number of electrons that would fill an atom's outer shell and make it nonreactive is ________.

Question 8

Anything that has mass and occupies space is considered to be ________.

Question 9

All isotopes of a given element have the same atomic mass.

Question 10

Two atoms that have the same chemical characteristics but different atomic masses are considered ________.

Question 11

Within the periodic table, elements are organized consecutively by

A) atomic mass within columns.
B) atomic mass within rows.
C) atomic number within columns.
D) atomic number within rows.

Question 12

Radioisotopes contain

A) an insufficient number of neutrons.
B) an insufficient number of electrons.
C) an insufficient number of protons.
D) an excess of protons.
E) an excess of neutrons.

Question 13

On the periodic table, beryllium sits above magnesium and to the right of lithium. Given that magnesium has two electrons in its outer shell and lithium has one, how many electrons would you predict beryllium has in its outer shell?

A) One
B) Two
C) Three
D) Four

Question 14

The three forms of matter are

A) air, water, and solids.
B) solids, liquids, and gases.
C) blood, bone, and air.
D) vapor, water, and solid.

Question 15

The half-life of a radioisotope is at least one day and at most ten years.

Question 16

The number of neutrons in an atom can be determined by

A) subtracting the atomic number from the atomic mass.
B) subtracting the atomic mass from the atomic number.
C) adding the atomic mass to the atomic number.
D) adding the number of protons to the number of electrons.
E) adding the number of protons to the atomic number.

Question 17

Biological half-life is the time required for

A) half of an ionic compound to ionize.
B) half of a radioactive material to be eliminated from the body.
C) radioactivity levels of organic compounds to stabilize at one-half their original value.
D) radiation exposure that is lethal for half of a biological population.

Question 18

Explain how the structure of an oxygen atom with an atomic mass of sixteen would be diagrammed. Include the number of subatomic particles in each part of the atom.

Question 19

An element's atomic number is determined by the number of ________ in one atom of that element.

A) protons
B) nuclei
C) electrons
D) neutrons
E) atomic mass units

Question 20

When diagramming an atom, how many electrons can fit in each of the shells beyond the innermost shell?

A) Two
B) Six
C) Eight
D) Ten

Question 21

The most common extracellular cation is ________.

Question 22

The molecular formula for bicarbonate ion is HCO₃^-. It is therefore a

A) polyatomic anion.
B) polyatomic cation.
C) radioactive isotope.
D) cationic compound.

Question 23

Which of the following is not one of the four most common elements in the body?

A) Oxygen
B) Nitrogen
C) Hydrogen
D) Carbon
E) Calcium

Question 24

If an ionic compound formed between an element from the first column of the periodic table and another from the sixth column, you would expect the compound to include

A) one atom from each of the two elements.
B) one atom from the first-column element and two atoms from the sixth-column element.
C) two atoms from the first-column element and one atom from the sixth-column element.
D) three atoms from the first-column element and two from the sixth-column element.

Question 25

Which statement accurately describes isomers?

A) They possess differing numbers of neutrons in their nuclei.
B) They have the same molecular shape but involve different elements.
C) They have the same structural formula but different molecular formulas.
D) They have the same molecular formula but different structural formulas.
E) They have gained or lost electrons at their outer shell.

Question 26

Elements in the first column of the periodic table contain one electron in their outer shell.

Question 27

Isomers of the same molecule have identical chemical properties.

Question 28

When atoms of elements on the left side of the periodic table ionize, they tend to

A) gain electrons and therefore become anions.
B) gain protons and therefore become anions.
C) lose electrons and therefore become cations.
D) lose protons and therefore become cations.
E) add neutrons and therefore become megaions.

Question 29

What is the number of covalent bonds that an atom of nitrogen can form within a molecule?

A) 1
B) 2
C) 3
D) 4

Question 30

Water contains two hydrogen atoms bound to one oxygen atom; "H₂O" is therefore water's

A) molecular formula.
B) ionic compound.
C) isotope ratio.
D) stochastic isomer.

Question 31

Ionic bonds involve

A) electrostatic interactions between anions and cations.
B) the sharing of electrons between two atoms of the same element.
C) the attraction between water and salts.
D) the release of protons by negatively charged particles.

Question 32

Positively charged ions are called cations.

Question 33

Describe the ionic form of calcium (what is its charge?). Then describe how three physiological systems would malfunction if calcium levels were not maintained homeostatically.

Question 34

An atom with a positive or negative charge is known as a(n) ________.

Question 35

Sodium bicarbonate (NaHCO₃) is considered an ionic compound.

Question 36

The numbers and types of atoms in a molecule as well as the spatial arrangement of those atoms is provided by the ________ formula.

Question 37

Phosphate ions are common cations within the body.

Question 38

An ion is an atom or group of atoms that has

A) a different number of neutrons than most atoms of that element.
B) lost or gained a proton.
C) lost or gained an electron.
D) a biological half-life due to radioactive decay.

Question 39

When elements found in column VIA of the periodic table become ions, they usually have a charge of

A) -2.
B) -1.
C) +1.
D) +2.
E) +3.

Question 40

In the formation of a compound of sodium chloride,

A) a chlorine atom donates an electron to a sodium atom.
B) a chloride ion donates two protons to a sodium ion.
C) a sodium atom donates an electron to a chlorine atom.
D) a sodium ion donates two electrons to a chlorine atom.
E) the sodium and chlorine atoms share a pair of electrons equally.

Question 41

An individual hydrogen bond in a sample of water would be described as

A) strong and intramolecular.
B) strong and intermolecular.
C) weak and intramolecular.
D) weak and intermolecular.

Question 42

When two atoms with very different electronegativity share electrons a polar covalent bond is formed.

Question 43

Consider an atom with four electrons in its outer shell. If that atom is covalently bound to three other atoms within a molecule, then it is

A) in a double bond with one atom and in single bonds with two atoms.
B) in a single bond with one atom and in double bonds with two atoms.
C) in a triple bond with one atom and in single bonds with two atoms.
D) in double bonds with all three atoms.
E) in single bonds with all three atoms.

Question 44

Hydrogen bonds form between molecules containing ________ bonds; the hydrogen bond is between a hydrogen atom of one molecule and a partially ________ charged atom of another.

A) polar covalent; negatively
B) polar covalent; positively
C) nonpolar covalent; positively
D) nonpolar covalent; negatively
E) ionic; positively

Question 45

Surfactant is necessary to prevent collapse of the alveoli in the lung because in its absence, water molecules

A) vaporize and take up much less space.
B) are more strongly attracted to each other by van der Waals forces.
C) are more strongly attracted to each other by cohesive forces.
D) congregate around nearby proteins to which they adhere.

Question 46

If an element from the first column of the periodic table entered into a covalent bond with one from the sixth column, then the bond would be a

A) polar bond, with the element from the first column developing a partial negative charge.
B) polar bond, with the element from the sixth column developing a partial negative charge.
C) nonpolar bond, with the element from the first column developing a partial positive charge.
D) nonpolar bond, with the element from the sixth column developing a partial positive charge.
E) nonpolar bond, with neither element developing any partial charges at all.

Question 47

Water has a

A) high specific heat, and this tends to cause large amounts of sweating.
B) high specific heat, and this tends to keep body temperature relatively constant.
C) low specific heat, and this tends to lead to variability in body temperature.
D) low specific heat, and this tends to minimize sweating.
E) low specific heat, and this tends to result in chills and shivering.

Question 48

Oxygen is more electronegative than carbon.

Question 49

The hydrogen bonds in a sample of water result in ________ cohesion and a ________ heat of vaporization.

A) increased; high
B) increased; low
C) decreased; high
D) decreased; low

Question 50

The molecular formula of chlorine gas is Cl₂. One molecule of this gas would be attracted to another by

A) polar covalent bonds.
B) intermolecular forces between nonpolar molecules.
C) ionic bonds.
D) hydrogen bonds.
E) intramolecular forces.

Question 51

A double covalent bond involves

A) the sharing of one pair of electrons.
B) the sharing of two pairs of electrons.
C) the donation of one pair of electrons.
D) the donation of two pairs of electrons.

Question 52

Phospholipids are described as

A) polar.
B) nonpolar.
C) amphipathic.
D) amphiprotic.

Question 53

Intermolecular forces between nonpolar molecules are weaker attractions than covalent bonds.

Question 54

Any molecule that contains a polar bond within it is a polar molecule.

Question 55

When a strong acid is placed in water, it

A) does not dissolve or dissociate.
B) dissolves but does not dissociate.
C) dissolves and dissociates.
D) dissociates, but does not dissolve.

Question 56

The amount of energy (measured in calories) required to increase the temperature of 1 gram of a substance by 1 degree Celsius is known as ________.

Question 57

Explain the attractive forces within and between molecules. In your answer, distinguish between polar and nonpolar bonds, and distinguish between single, double, and triple bonds. Also be sure to explain three types of intermolecular attractions.

Question 58

Water is the main solute of the body.

Question 59

Fatty acids consist mainly of carbon and hydrogen, and so fatty acids are

A) nonpolar and do not dissolve in water.
B) nonpolar and dissolve in water.
C) polar and do not dissolve in water.
D) polar and dissolve in water.

Question 60

An individual water molecule contains ________ atoms and enters into ________ hydrogen bonds with other water molecules.

A) two; two
B) three; two
C) three; three
D) three; four
E) three; six

Question 61

When a protein of 50 nanometers is mixed with water, the opaque result is called a(n)

A) suspension.
B) emulsion.
C) solution.
D) colloid.

Question 62

"Hydrophobic exclusion" refers to the chemical interactions that prevent nonpolar molecules from dissolving in water.

Question 63

A hydroxide ion carries a negative charge.

Question 64

Bicarbonate (HCO₃^-) is a

A) strong proton donor.
B) strong proton acceptor.
C) weak proton donor.
D) weak proton acceptor.

Question 65

The addition of a buffer to liquid such as blood with a pH of 7.4 causes the pH to drop to 7.0 (chemically neutral).

Question 66

A base is described as a proton donor.

Question 67

The higher the concentration of H⁺ is, the lower the pH is.

Question 68

Steroid hormones are nonpolar molecules that travel in the blood. Explain how such molecules interact with the water of the plasma.

Question 69

An emulsion is a combination of water and a nonpolar liquid that have been forcibly mixed.

Question 70

Chemical barriers composed of phospholipid bilayers form within biological systems because

A) cells expend ATP to position the phospholipid tails close together.
B) hydrophobic exclusion results in the close positioning of the nonpolar tails.
C) van der Waals forces attract the polar heads to the water inside the cell.
D) the inability of the polar heads to dissolve in water causes the heads to adhere to one another.

Question 71

Given a watery solution in which 1/1,000,000 particles are free H⁺ ions, what will the pH be?

A) 2
B) 5
C) 6
D) 7
E) 10

Question 72

Compared to a solution with a pH of 7, a solution with a pH of 4 is

A) more acidic and has a 1,000-fold increase in [H⁺].
B) more acidic and has a 300-fold increase in [H⁺].
C) more basic and has a 1,000-fold increase in [H⁺].
D) more basic and has a 300-fold increase in [H⁺].
E) more basic and has a 300-fold decrease in [H⁺].

Question 73

Which of the following statements accurately describes the solutes within a solution?

A) Water is the universal solute, and solutes are more abundant in solutions than solvents are.
B) The solutes are not visible, do not scatter light, and do not settle if the solution is left standing.
C) Solutes are greater than 1 millimeter in size, and will settle out of solution if the mixture is left standing.
D) Solutes are between 1 nanometer and 1 millimeter in size; they do not scatter light but will settle out of solution if left standing.

Question 74

When a nonpolar molecule is placed in water, it will

A) neither dissolve nor carry electrical current.
B) dissolve and carry electrical current.
C) dissociate and carry electrical current.
D) carry electrical current but not dissolve or dissociate.

Question 75

Generally, a chemical buffer is described as

A) a strong acid or strong base that brings the pH of a solution to 7.0.
B) a weak acid and weak base that help prevent big changes in pH.
C) a neutral molecule that does not influence the pH in any way.
D) a weak acid that makes a solution slightly more basic by its presence.

Question 76

When water mixtures are formed, the components are chemically altered and the new molecular bonds can be separated only by chemical means.

Question 77

When the pH of an acidic solution is brought to 7.0, that change is called ________.

Question 78

In a sample of distilled water, a water molecule that has picked up an extra hydrogen ion is called a(n)

A) amphipathic macromolecule.
B) hydroxide ion.
C) hydronium ion.
D) proteinaceous water molecule.

Question 79

A molecule with polar and nonpolar parts that only partially dissolves in water is described as ________.

Question 80

To neutralize a base, a(n) ________ must be added.

A) acid
B) buffer
C) weak base
D) hydroxide ion