Chapter 2 Questions

A key defining feature between eukaryotes and prokaryotes is the presence of __.

A) DNA
B) A cytoplasm
C) A cell membrane
D) A membrane-enclosed nucleus

In which domain would you find humans?

A) Eukarya
B) Archaea
C) Prokarya
D) Animalia

Genes are long molecules of ___, which encode proteins or RNAs that perform some function in the cell

A) Chromosomes
B) Genomes
C) DNA
D) RNA

An electron orbital describes:

A) The orbit of an electron around the nucleus
B) The exact distance of an electron from the nucleus
C) None of the above
D) A three-dimensional space where an electron can be found 90% of the time

Which of the following bonds can form between atoms of equal electronegativity?

A) None of these
B) Van der Waals bonds
C) Hydrogen bonds
D) Ionic bonds

Which electron has higher potential energy?

A) None of these
B) An electron in the first electron shell
C) An electron in the third electron shell
D) Both electrons have equal potential energy

H20 can be considered ___, but H2 can only be considered ___.

All atoms of the same element have the same number of protons (p=6) but may differ in the number of neutrons. Carbon-13 is an example of a carbon isotope with how many neutrons?

A) 17
B) 6
C) 7
D) 13

Titanium has an atomic number of 22. How many protons(p), neutrons(n), and electrons (e) are in an isotope with mass 48?

A) 22(p), 22(n), 22(e)
B) 22(p), 22(n), 26(e)
C) 26(p), 26(n), 22(e)
D) 22(p), 26(n), 22(e)

A cation is positively charged because it has ___ electron(s).

A) accepted
B) equally shared
C) doubled
D) lost

How many electrons are involved in  double covalent bond?

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

How many electrons pairs are shared between carbon atoms in a molecule that has the formula C2H4?

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

Magnesium has an atomic number of 12. What is the most stable charge for a magnesium ion?

A) +2
B) -1
C) +1
D) -2

Which electron has higher potential energy?

A) Electrons do not have potential energy
B) Both electrons have equal potential energy
C) An electron in the third electron shell
D) An electron in the first electron shell

What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms?

A) 6
B) 4
C) 2
D) 8

What is the difference between covalent bonds and ionic bonds?

A) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms
B) Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms
C) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms
D) Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms

A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a ___.

A) surface of mostly carbon-nitrogen bonds
B) slightly damp surface
C) surface of mostly carbon-oxygen bonds
D) surface of hydrocarbons

Which of the following dissociates completely in solution and is considered to be a strong base (alkali)?

A) HCl
B) NH3
C) H2CO3
D) NaOH

Which of the following takes place as an ice cube cools a drink?

A) A calorie of heat energy is transferred from the ice to the water of the drink
B) Kinetic energy in the liquid water decreases
C) Molecular collisions in the drink increase.
D) The specific heat of the water in the drink decreases

Water molecules can form hydrogen bonds with ___.

A) chloride ions
B) compounds that have polar covalent bonds
C) oxygen gas (O2) molecules
D) oils

A 0.01M solution of a substance has a pH of 2. What can you conclude about this substance?

A) It is a strong base that dissociates completely in water
B) It is a weak acid
C) It is a weak base
D) It is a strong acid that dissociates completely in water

Why does ice float in liquid water?

A) The crystalline lattice of ice causes it to be denser than liquid water
B) The ionic bonds between the molecules in ice prevent the ice from sinking
C) The high surface tension of liquid water keeps the ice on top
D) Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water

Hydrophobic substances such as vegetable oil are ___.

A) polar substances that have an affinity for water
B) nonpolar substances that repel water molecules
C) polar substances that repel water molecules
D) nonpolar substances that have an attraction for water molecules

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is the attraction called?

A) a hydrogen bond
B) an ionic bond
C) a covalent bond
D) a van der Waals interaction

Van der Waals interactions may result when ___.

A) two polar covalent bonds react
B) electrons are not symmetrically distributed in a molecule
C) molecules held by ionic bonds react with water
D) a hydrogen atom loses an electron

An electron shell describes:

A) The average distance of an electron from the nucleus
B) Both the average distance of an electron from the nucleus and the potential energy of an electron
C) The orbit of an electron around the nucleus
D) The potential energy of an electron

If an atom has a charge of +1, which of the following must be true?

A) It has the same number of protons as electrons
B) It has one more electron than it does protons
C) It has two more protons than neutrons
D) It has one more proton than it does electrons

Which type of bond must be broken for water to vaporize?

A) hydrogen bonds
B) polar covalent bonds
C) Ionic bonds
D) both polar covalent bonds and hydrogen bonds